Tìm x biết:
1. 5x bình - 2x - 7 = 0
2. x bình - 10x - 11 = 0
3. x bình - 7x - 8 = 0
4. x bình + 9x + 8 = 0
5. x bình - 5x - 6 = 0
Các bác giúp e vs, hứa sẽ tick, e cảm ơn !!!!!!!!!!!!!!!!!!!!
Những câu hỏi liên quan
Tìm x biết:
1. x bình - 8x + 7 = 0
2. 5x bình -11x + 6 = 0
3. 2x bình - 3x + 1 = 0
4. x bình + 7x - 8 = 0
5. 3x bình + 7x - 10= 0
Các bác giúp e vs, hứa sẽ tick, e cảm ơn !!!!!!!!!!!!!!!!
1) \(x^2-8x+7=0\)
\(\Leftrightarrow x^2-7x-x+7=0\)
\(\Leftrightarrow\left(x^2-7x\right)-\left(x-7\right)=0\)
\(\Leftrightarrow x\left(x-7\right)-\left(x-7\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(x-7\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\x-7=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=7\end{matrix}\right.\)
2) \(5x^2-11x+6=0\)
\(\Leftrightarrow5x^2-5x-6x+6=0\)
\(\Leftrightarrow\left(5x^2-5x\right)-\left(6x-6\right)=0\)
\(\Leftrightarrow5x\left(x-1\right)-6\left(x-1\right)=0\)
\(\Leftrightarrow\left(5x-6\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}5x-6=0\\x-1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{6}{5}\\x=1\end{matrix}\right.\)
3) \(2x^2-3x+1=0\)
\(\Leftrightarrow2x^2-2x-x+1=0\)
\(\Leftrightarrow\left(2x^2-2x\right)-\left(x-1\right)=0\)
\(\Leftrightarrow2x\left(x-1\right)-\left(x-1\right)=0\)
\(\Leftrightarrow\left(2x-1\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}2x-1=0\\x-1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=1\end{matrix}\right.\)
4) \(x^2+7x-8=0\)
\(\Leftrightarrow x^2+8x-x-8=0\)
\(\Leftrightarrow\left(x^2+8x\right)-\left(x+8\right)=0\)
\(\Leftrightarrow x\left(x+8\right)-\left(x+8\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(x+8\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\x+8=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-8\end{matrix}\right.\)
5) \(3x^2+7x-10=0\)
\(\Leftrightarrow3x^2-3x+10x-10=0\)
\(\Leftrightarrow\left(3x^2-3x\right)+\left(10x-10\right)=0\)
\(\Leftrightarrow3x\left(x-1\right)+10\left(x-1\right)=0\)
\(\Leftrightarrow\left(3x+10\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}3x+10=0\\x-1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{10}{3}\\x=1\end{matrix}\right.\)
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1) (4-3x) (10x-5)02) (7-2x) (4+8x) 03) (9-7x) (11-3x) 04) (7-14x) (x-2) 05) (2x+1) (x-3) 06) (8-3x) (-3x+5) 07) (16-8x) (2-6x) 08) (x+4) (6x-12) 09) (11-33x) (x+11) 010) (x-1/4) (x+5/6) 011) (7/8-2x) (3x+1/3) 012) 3x - 2x^2 013) 5x + 10x^2 014) 4x + 3x^2 015) -8x^2 + x 016) 10x^2 - 15x 017) x^2 -4 018) 9 - x^2 019) x^2 -1 020) (x-3) (2x-1) (2x-1) ( 2x+3)21) (5+4x) (-x+2) (5+4x) (7+5x)22) (4+x) (x-5) (3x-8) (x-5) 0 23) (3x-8) (7-21x) - (9+2x) (7-21x)24) (10+ 7x) (x+1) (9x-2)(...
Đọc tiếp
1) (4-3x) (10x-5)=0
2) (7-2x) (4+8x) = 0
3) (9-7x) (11-3x) = 0
4) (7-14x) (x-2) = 0
5) (2x+1) (x-3) = 0
6) (8-3x) (-3x+5) = 0
7) (16-8x) (2-6x) = 0
8) (x+4) (6x-12) = 0
9) (11-33x) (x+11) = 0
10) (x-1/4) (x+5/6) = 0
11) (7/8-2x) (3x+1/3) = 0
12) 3x - 2x^2 = 0
13) 5x + 10x^2 = 0
14) 4x + 3x^2 = 0
15) -8x^2 + x =0
16) 10x^2 - 15x = 0
17) x^2 -4 =0
18) 9 - x^2 = 0
19) x^2 -1 = 0
20) (x-3) (2x-1) = (2x-1) ( 2x+3)
21) (5+4x) (-x+2) = (5+4x) (7+5x)
22) (4+x) (x-5) = (3x-8) (x-5) = 0
23) (3x-8) (7-21x) - (9+2x) (7-21x)
24) (10+ 7x) (x+1) = (9x-2)(x-1)
25) (9x-4) (x-1/2) - (x-1/2) (6+x) = 0
26) 9x^2 - 1 = (3x-1) (x+4)
27) (x+7) (3x+1) = 49-x^2
28) (2x+1)^2 = (x-1)^2
29)x^3- 5x^2+6x = 0
30) 3x^2 + 5x + 2 = 0
Giảii giúpp mìnhh đyy mọii ngườii .
\(\left(4-3x\right)\left(10x-5\right)=0\)
\(\Rightarrow\orbr{\begin{cases}4-3x=0\\10x-5=0\end{cases}\Rightarrow\orbr{\begin{cases}3x=4\\10x=5\end{cases}\Rightarrow}\orbr{\begin{cases}x=\frac{4}{3}\\x=\frac{1}{2}\end{cases}}}\)
\(\left(7-2x\right)\left(4+8x\right)=0\)
\(\Rightarrow\orbr{\begin{cases}7-2x=0\\4+8x=0\end{cases}\Rightarrow\orbr{\begin{cases}2x=7\\8x=-4\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{7}{2}\\x=-\frac{1}{2}\end{cases}}}}\)
rồi thực hiện đến hết ...
Brainchild bé ngây thơ qus e , ko thực hiện đến hết như thế đc đâu :>
\(\left(x-3\right)\left(2x-1\right)=\left(2x-1\right)\left(2x+3\right)\)
\(2x^2-7x+3=4x^2+4x-3\)
\(2x^2-7x+3-4x^2-4x+3=0\)
\(-2x^2-11x+6=0\)
\(2x^2+11x-6=0\)
\(2x^2+12x-x-6=0\)
\(2x\left(x+6\right)-\left(x+6\right)=0\)
\(\left(x+6\right)\left(2x-1\right)=0\)
\(x+6=0\Leftrightarrow x=-6\)
\(2x-1=0\Leftrightarrow2x=1\Leftrightarrow x=\frac{1}{2}\)
\(3x-2x^2=0\)
\(x\left(2x-3\right)=0\)
\(x=0\)
\(2x-3=0\Leftrightarrow2x=3\Leftrightarrow x=\frac{3}{2}\)
Tự lm tiếp nha
1GIẢI PHƯƠNG TRÌNH
A 2x-6=0
B x(x+2)-3(x+2)=0
C x-6 phần x+1=x bình phương phần x-1
2 TÌM ĐKXĐ
A 2-x phần x-3= 0
B x bình-3 phần 3x-2=5x+4 phần 9x bình-4
BẠN NAOF PÍT LÀM,GIÚP MÌNH NHA
1)
a) \(2x-6=0\)
\(\Leftrightarrow2x=6\)
\(\Leftrightarrow x=3\)
b) \(x\times\left(x+2\right)-3\times\left(x+2\right)=0\)
\(\Leftrightarrow\left(x-3\right)\times\left(x+2\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x-3=0\\x+2=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=3\\x=-2\end{cases}}\)
c) \(\frac{x-6}{x+1}=\frac{x^2}{x-1}\)
nhân chéo lên, ngại chết đc
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Giải phương trình
1) 16-8x=0
2) 7x+14=0
3) 5-2x=0
4) 3x-5=7
5) 8-3x=6
6) 8=11x+6
7)-9+2x=0
8) 7x+2=0
9) 5x-6=6+2x
10) 10+2x=3x-7
11) 5x-3=16-8x
12)-7-5x=8+9x
13) 18-5x=7+3x
14) 9-7x=-4x+3
15) 11-11x=21-5x
16) 2(-7+3x)=5-(x+2)
17) 5(8+3x)+2(3x-8)=0
18) 3(2x-1)-3x+1=0
19)-4(x-3)=6x+(x-3)
20)-5-(x+3)=2-5x
20) -5-(x + 3) = 2 - 5x ⇔ -5 - x - 3 = 2 -5x ⇔ 4x = 10 ⇔ x = \(\frac{5}{2}\)
Vậy...
https://i.imgur.com/PCDykdb.jpg
1) 16 - 8x = 0 ⇔ 8(2 - x) = 0⇔ 2 - x = 0 ⇔ x = 2
Vậy phương trình có nghiệm là x = 2
Xem thêm câu trả lời
1).(4-3x)(10-5x)=0 2).(7-2x)(4+8x)=0 3).(9-7x)(11-3x)=0
4).(7-14x)(x-2)=0 5).(\(\dfrac{7}{8}\)-2x)(3x+\(\dfrac{1}{3}\))=0 6).3x-2x\(^2\)
7).5x+10x\(^2\)
1.
<=> \(\left[{}\begin{matrix}4-3x=0\\10-5x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{4}{3}\\x=2\end{matrix}\right.\)
2.
<=>\(\left[{}\begin{matrix}7-2x=0\\4+8x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{7}{2}\\x=-\dfrac{1}{2}\end{matrix}\right.\)
3.
<=>\(\left[{}\begin{matrix}9-7x=0\\11-3x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{9}{7}\\x=\dfrac{11}{3}\end{matrix}\right.\)
4.
<=>\(\left[{}\begin{matrix}7-14x=0\\x-2=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=2\end{matrix}\right.\)
5.
<=>\(\left[{}\begin{matrix}\dfrac{7}{8}-2x=0\\3x+\dfrac{1}{3}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{7}{16}\\x=-\dfrac{1}{9}\end{matrix}\right.\)
6,7. ko đủ điều kiện tìm
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Giải phương trình
1) 16-8x=0
2) 7x+14=0
3) 5-2x=0
4) 3x-5=7
5) 8-3x=6
6) 8=11x+6
7)-9+2x=0
8) 7x+2=0
9) 5x-6=6+2x
10) 10+2x=3x-7
11) 5x-3=16-8x
12)-7-5x=8+9x
13) 18-5x=7+3x
14) 9-7x=-4x+3
15) 11-11x=21-5x
16) 2(-7+3x)=5-(x+2)
17) 5(8+3x)+2(3x-8)=0
18) 3(2x-1)-3x+1=0
19)-4(x-3)=6x+(x-3)
20)-5-(x+3)=2-5x
Mấy cái này chuyển vế đổi dấu là xong í mà :3
1,
16-8x=0
=>16=8x
=>x=16/8=2
2,
7x+14=0
=>7x=-14
=>x=-2
3,
5-2x=0
=>5=2x
=>x=5/2
Mk làm 3 cau làm mẫu thôi
Lúc đăng đừng đăng như v :>
chi ra khỏi ngt nản
từ câu 1 đến câu 8 cs thể làm rất dễ,bn tham khảo bài của bn muwaa r làm những câu cn lại
1, 16 - 8x = 0
<=>-8x = 16
<=> x = -2
Vậy_
2, 7x + 14 = 0
<=> 7x = -14
<=> x = -2
3, 5 - 2x = 0
<=> - 2x = -5
<=> x =\(\frac{5}{2}\)
Vậy_
4, 3x - 5 = 7
<=> 3x = 7 + 5
<=> 3x = 12
<=> x = 4
Vậy...
5, 8 - 3x = 6
<=> - 3x = 6 - 8
<=> -3x = - 2
<=> x =\(\frac{2}{3}\)
Vậy......
Tìm số tự nhiên x biết:
(x+2)-2=0
(x+3)+1=7
(3x-4)+4=12
(5x+4)-1=13
(4x-8)-3=5
8-(2x-4)=2
7+(5x+2)=14
5-(3x-11)=1
Giúp e vs ạ(Vui lòng trình bày ạ)
\(\left(x+2\right)-2=0\)
\(\Rightarrow x+2-2=0\)
\(\Rightarrow x=0\)
\(\left(x+3\right)+1=7\)
\(\Rightarrow x+3+1=7\)
\(\Rightarrow x+4=7\)
\(\Rightarrow x=3\)
\(\left(3x-4\right)+4=12\)
\(\Rightarrow3x-4+4=12\)
\(\Rightarrow3x=12\)
\(\Rightarrow x=4\)
\(\left(5x+4\right)-1=13\)
\(\Rightarrow5x+4-1=13\)
\(\Rightarrow5x+3=13\)
\(\Rightarrow5x=10\)
\(\Rightarrow x=2\)
\(\left(4x-8\right)-3=5\)
\(\Rightarrow4x-8-3=5\)
\(\Rightarrow4x-11=5\)
\(\Rightarrow4x=16\)
\(\Rightarrow x=4\)
\(8-\left(2x+4\right)=2\)
\(\Rightarrow8-2x-4=2\)
\(\Rightarrow4-2x=2\)
\(\Rightarrow2x=2\)
\(\Rightarrow x=1\)
\(7+\left(5x+2\right)=14\)
\(\Rightarrow7+5x+2=14\)
\(\Rightarrow9+5x=14\)
\(\Rightarrow5x=5\)
\(\Rightarrow x=1\)
\(5-\left(3x-11\right)=1\)
\(\Rightarrow5-3x+11=1\)
\(\Rightarrow16-3x=1\)
\(\Rightarrow3x=15\)
\(\Rightarrow x=5\)
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Tìm x biết:
1. -6x bình - x + 7 =0
2. -4x bình - 5x + 9 = 0
3. x bình + 3x - 4 = 0
4. x bình - 6x - 7 = 0
5. x bình + 5x + 4 = 0
Các bác giúp e vs ak, hứa sẽ tick, e cảm ơn nhiều
@nguyen thi vang bác giúp e vs ak, e cảm ơn nhiều!!!!!!!!!!!!!!!!!!!!
1) \(-6x^2-x+7=0\)
\(\Leftrightarrow-6x^2+6x-7x+7=0\)
\(\Leftrightarrow\left(-6x^2+6x\right)-\left(7x-7\right)=0\)
\(\Leftrightarrow-6x\left(x-1\right)-7\left(x-1\right)=0\)
\(\Leftrightarrow\left(-6x-7\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}-6x-7=0\\x-1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{7}{6}\\x=1\end{matrix}\right.\)
2) \(-4x^2-5x+9=0\)
\(\Leftrightarrow-4x^2+4x-9x+9=0\)
\(\Leftrightarrow\left(-4x^2+4x\right)-\left(9x-9\right)=0\)
\(\Leftrightarrow-4x\left(x-1\right)-9\left(x-1\right)=0\)
\(\Leftrightarrow\left(-4x-9\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}-4x-9=0\\x-1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{9}{4}\\x=1\end{matrix}\right.\)
3) \(x^2+3x-4=0\)
\(\Leftrightarrow x^2-x+4x-4=0\)
\(\Leftrightarrow\left(x^2-x\right)+\left(4x-4\right)=0\)
\(\Leftrightarrow x\left(x-1\right)+4\left(x-1\right)=0\)
\(\Leftrightarrow\left(x+4\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x+4=0\\x-1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-4\\x=1\end{matrix}\right.\)
4) \(x^2-6x-7=0\)
\(\Leftrightarrow x^2+x-7x-7=0\)
\(\Leftrightarrow\left(x^2+x\right)-\left(7x+7\right)=0\)
\(\Leftrightarrow x\left(x+1\right)-7\left(x+1\right)=0\)
\(\Leftrightarrow\left(x-7\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-7=0\\x+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=7\\x=-1\end{matrix}\right.\)
5) \(x^2+5x+4=0\)
\(\Leftrightarrow x^2+x+4x+4=0\)
\(\Leftrightarrow\left(x^2+x\right)+\left(4x+4\right)=0\)
\(\Leftrightarrow x\left(x+1\right)+4\left(x+1\right)=0\)
\(\Leftrightarrow\left(x+4\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x+4=0\\x+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-4\\x=-1\end{matrix}\right.\)
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Bình luận (3)
a) \(-6x^2-x+7=0\)
\(\Leftrightarrow-6x^2+6x-7x+7=0\)
\(\Leftrightarrow-6x\left(x-1\right)-7\left(x-1\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(-6x-7\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=\dfrac{-7}{6}\end{matrix}\right.\)
b) \(-4x^2-5x+9=0\)
\(\Leftrightarrow-4x^2+4x-9x+9=0\)
\(\Leftrightarrow-4x\left(x-1\right)-9\left(x-1\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(-4x-9\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-2,25\end{matrix}\right.\)
c) \(x^2+3x-4=0\)
\(\Leftrightarrow x^2-x+4x-4=0\)
\(\Leftrightarrow x\left(x-1\right)+4\left(x-1\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(x+4\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-4\end{matrix}\right.\)
d) \(x^2-6x-7=0\)
\(\Leftrightarrow x^2+x-7x-7=0\)
\(\Leftrightarrow x\left(x+1\right)-7\left(x+1\right)=0\)
\(\Leftrightarrow\left(x+1\right)\left(x-7\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-1\\x=7\end{matrix}\right.\)
e) \(x^2+5x+4=0\)
\(\Leftrightarrow x^2+x+4x+4=0\)
\(\Leftrightarrow x\left(x+1\right)+4\left(x+1\right)=0\)
\(\Leftrightarrow\left(x+1\right)\left(x+4\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-1\\x=-4\end{matrix}\right.\)
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1/
x=1;x=\(-\dfrac{7}{6}\)
2/
x=1;x=\(-\dfrac{9}{4}\)
3/
x=1;x=-1
4/
x=7;x=-1
5/
x=-1;x=-4
GIẢI RA LẢN LẮM!!
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Bài 1: CMR các đa thức sau luôn dương vs mọi giá trị biến số:a) x^2 + x +1b) x^2 + 3x+3c) x^2 + y^2 + 2(x-2y) +6d) 2x^2 + y^2 + 2x( y-1) +2Bài 2: Phân tích thành nhân tử:a) x^2 + 2x-3b) x^2 - 10x +9c) x^2 - 2x -15d) x^2 - 2x -48e) x^2 - 10x+24f)4x^2 + 4x -15g) 3x^2 - 7x +2h) 4x^2 - 5x +1Bài 3: Tìm x biết :a) x^2 +5x+60b) x^2 - 10x + 160c) x^2 - 10x +210d) x^2 - 2x -3 0e) 2x^2 + 7x +30f) x^2 - x- 60Bài 4:a)x^3 + 2x^2 - 30b) x^3 - 7x -60c) x^3 + x^2 +40d) x^3 - 2x^2 - x+2 0lm giups mk vs ạ,mk cảm...
Đọc tiếp
Bài 1: CMR các đa thức sau luôn dương vs mọi giá trị biến số:
a) x^2 + x +1
b) x^2 + 3x+3
c) x^2 + y^2 + 2(x-2y) +6
d) 2x^2 + y^2 + 2x( y-1) +2
Bài 2: Phân tích thành nhân tử:
a) x^2 + 2x-3
b) x^2 - 10x +9
c) x^2 - 2x -15
d) x^2 - 2x -48
e) x^2 - 10x+24
f)4x^2 + 4x -15
g) 3x^2 - 7x +2
h) 4x^2 - 5x +1
Bài 3: Tìm x biết :
a) x^2 +5x+6=0
b) x^2 - 10x + 16=0
c) x^2 - 10x +21=0
d) x^2 - 2x -3 =0
e) 2x^2 + 7x +3=0
f) x^2 - x- 6=0
Bài 4:
a)x^3 + 2x^2 - 3=0
b) x^3 - 7x -6=0
c) x^3 + x^2 +4=0
d) x^3 - 2x^2 - x+2 =0
lm giups mk vs ạ,mk cảm ơn rất nhiều
dễ mà, rảnh ỗi đăng cái đề ko đâu vào đâulên làm j, cái này dùng hằng đẳng thức cân hết được à
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