Tìm x:
a) 1+3+5+......+x=1600
b) 5.(x-1)+2x=4-2x
c) 6(x-2)-5x=4
d) 4x+2(3x-1)=11-x
e) 2(x-1)-5(2-3x)=19
f) (3x-5)-(4-8x)=6+x
g) 4x-5=4.(3-2x)+7
Tìm x biết :
a, 4.(18 - 5x) - 12.(3x - 7) = 15.(2x - 16) - 6(x + 14)
b, 5.(3x + 5) - 4.(2x - 3) = 5x + 3.(2x + 12) + 1
c, 2.(5x - 8) - 3.(4x - 5) = 4.(3x - 4) + 11
d, (3x + 2)(2x + 9) - (x + 2)(6x + 1) = (x + 1) - (x - 6)
e, (8x - 3)(3x + 2) - (4x + 7)(x + 4)= (2x + 1)(5x - 1) - 33
Noob ơi, bạn phải đưa vào máy tính ý solve cái là ra x luôn, chỉ tội là đợi hơi lâu
a, 4.(18 - 5x) - 12(3x - 7) = 15(2x - 16) - 6(x + 14)
=> 72 - 20x - 36x + 84 = 30x - 240 - 6x - 84
=> (72 + 84) + (-20x - 36x) = (30x - 6x) + (-240 - 84)
=> 156 - 56x = 24x - 324
=> 24x + 56x = 324 + 156
=> 80x = 480
=> x = 480 : 80 = 6
Vậy x = 6
b, 5(3x + 5) - 4(2x - 3) = 5x + 3(2x + 12) + 1
=> 15x + 25 - 8x + 12 = 5x + 6x + 36 + 1
=> (15x - 8x) + (25 + 12) = 11x + 37
=> 7x + 37 = 11x + 37
=> 11x - 7x = 0
=> x = 0
giải các phương trình sau:
a) 4x.(2x+3) - x.(8x-1)= 5.(x+2)
b) (3x-5).(3x+5) - x.(9x-1) = 4
c) 3 - 4x . (25-2x) = 8x^2 + x - 300
d) 2. (1-3x/5) - 2+3x/10 = 7-3.(2x+1)/4
e) 5x + 2/6 - 8x - 1 /3 = 4x + 2 /5 - 5
f) 5x - 4/2 = 16x + 1/7
g) 12x + 5 / 3=2x - 7/4
h) 3t - 8/12 = 5-t /8
i) 5u + 6/15 = u - 4 /10
k) 3.(x-11)/4 = 3. (x+1) - 2.(2x+ 5)/10
l) 14 và 1/2 - 2. (x+3)/5 = 3x/2 - 2. (x-7 )/3
m ) 2x -5 / 6 - x +2 = 5x - 3/ 3 - 6x - 7/ 4 + x
n) x-4/5 + 3x - 2/10 - x = 2x-5/3 - 7x+2/6
mình đang cần gấp
giải các phương trình sau:
a) 4x.(2x+3) - x.(8x-1)= 5.(x+2)
b) (3x-5).(3x+5) - x.(9x-1) = 4
c) 3 - 4x . (25-2x) = 8x^2 + x - 300
d) 2. (1-3x/5) - 2+3x/10 = 7-3.(2x+1)/4
e) 5x + 2/6 - 8x - 1 /3 = 4x + 2 /5 - 5
f) 5x - 4/2 = 16x + 1/7
g) 12x + 5 / 3=2x - 7/4
h) 3t - 8/12 = 5-t /8
i) 5u + 6/15 = u - 4 /10
k) 3.(x-11)/4 = 3. (x+1) - 2.(2x+ 5)/10
l) 14 và 1/2 - 2. (x+3)/5 = 3x/2 - 2. (x-7 )/3
m ) 2x -5 / 6 - x +2 = 5x - 3/ 3 - 6x - 7/ 4 + x
n) x-4/5 + 3x - 2/10 - x = 2x-5/3 - 7x+2/6
mình đang cần gấp
giải các phương trình sau:
a) 4x.(2x+3) - x.(8x-1)= 5.(x+2)
b) (3x-5).(3x+5) - x.(9x-1) = 4
c) 3 - 4x . (25-2x) = 8x^2 + x - 300
d) 2. (1-3x/5) - 2+3x/10 = 7-3.(2x+1)/4
e) 5x + 2/6 - 8x - 1 /3 = 4x + 2 /5 - 5
f) 5x - 4/2 = 16x + 1/7
g) 12x + 5 / 3=2x - 7/4
h) 3t - 8/12 = 5-t /8
i) 5u + 6/15 = u - 4 /10
k) 3.(x-11)/4 = 3. (x+1) - 2.(2x+ 5)/10
l) 14 và 1/2 - 2. (x+3)/5 = 3x/2 - 2. (x-7 )/3
m ) 2x -5 / 6 - x +2 = 5x - 3/ 3 - 6x - 7/ 4 + x
n) x-4/5 + 3x - 2/10 - x = 2x-5/3 - 7x+2/6
mình đang cần gấp
giải các phương trình sau:
a) 4x.(2x+3) - x.(8x-1)= 5.(x+2)
b) (3x-5).(3x+5) - x.(9x-1) = 4
c) 3 - 4x . (25-2x) = 8x^2 + x - 300
d) 2. (1-3x/5) - 2+3x/10 = 7-3.(2x+1)/4
e) 5x + 2/6 - 8x - 1 /3 = 4x + 2 /5 - 5
f) 5x - 4/2 = 16x + 1/7
g) 12x + 5 / 3=2x - 7/4
h) 3t - 8/12 = 5-t /8
i) 5u + 6/15 = u - 4 /10
k) 3.(x-11)/4 = 3. (x+1) - 2.(2x+ 5)/10
l) 14 và 1/2 - 2. (x+3)/5 = 3x/2 - 2. (x-7 )/3
m ) 2x -5 / 6 - x +2 = 5x - 3/ 3 - 6x - 7/ 4 + x
n) x-4/5 + 3x - 2/10 - x = 2x-5/3 - 7x+2/6
mình đang cần gấp
giải các phương trình sau:
a) 4x.(2x+3) - x.(8x-1)= 5.(x+2)
b) (3x-5).(3x+5) - x.(9x-1) = 4
c) 3 - 4x . (25-2x) = 8x^2 + x - 300
d) 2. (1-3x/5) - 2+3x/10 = 7-3.(2x+1)/4
e) 5x + 2/6 - 8x - 1 /3 = 4x + 2 /5 - 5
f) 5x - 4/2 = 16x + 1/7
g) 12x + 5 / 3=2x - 7/4
h) 3t - 8/12 = 5-t /8
i) 5u + 6/15 = u - 4 /10
k) 3.(x-11)/4 = 3. (x+1) - 2.(2x+ 5)/10
l) 14 và 1/2 - 2. (x+3)/5 = 3x/2 - 2. (x-7 )/3
m ) 2x -5 / 6 - x +2 = 5x - 3/ 3 - 6x - 7/ 4 + x
n) x-4/5 + 3x - 2/10 - x = 2x-5/3 - 7x+2/6
mình đang cần gấp
a,\(4x\left(2x+3\right)-x\left(8x-1\right)=5\left(x+2\right)\)
\(< =>8x^2+12x-8x^2+x=5x+10\)
\(< =>13x=5x+10< =>8x=10\)
\(< =>x=\frac{10}{8}=\frac{5}{4}\)
b, \(\left(3x-5\right)\left(3x+5\right)-x\left(9x-1\right)=4\)
\(< =>9x^2-25-9x^2+x=4\)
\(< =>x=4+29=33\)
c,\(3-4x\left(25-2x\right)=8x^2+x-300\)
\(< =>3-100x+8x^2=8x^2+x-300\)
\(< =>x+100x=3+300\)
\(< =>101x=303< =>x=\frac{303}{101}=3\)
d,\(2\left(1-\frac{3x}{5}\right)-\frac{2+3x}{10}=7-\frac{3\left(2x+1\right)}{4}\)
\(< =>2-\frac{6x}{5}-\frac{2+3x}{10}=7-\frac{6x+3}{4}\)
\(< =>-\frac{24x}{20}-\frac{4+6x}{20}+\frac{30x+15}{20}=5\)
\(< =>\frac{30x-6x-24x+15-4}{20}=5\)
\(< =>\frac{11}{5}=5< =>11=25\)(vo li)
e, \(\frac{5x+2}{6}-\frac{8x-1}{3}=\frac{4x+2}{5}-5\)
\(< =>\frac{25x+10}{30}-\frac{80x-10}{30}=\frac{24x+12}{30}-5\)
\(< =>\frac{24x+12+80x-10-25x-10}{30}=5\)
\(< =>79x-8=150\)
\(< =>79x=150+8< =>x=\frac{158}{79}\)
các bạn giúp mik bài này vs
5) (4x-5).(x+2)-(x+5).(x-3)-3x^2-x
6) (x-3).(x+7)-(2x-1).(x+2)+x.(x-1)
7) (7x-3).(2x+1)-(5x-2).(x+4)-9x^2+17x
8) -2.(x-7).(x+3)+(5x-1).(x+4)-3x^2-27x
9) (6x-5).(x+8)-(3x-1).(2x+3)-9.(4x-3)
10) (8x-1).(x+7)-(x-2).(8x+5)-11.(6x+1).
một đòn bẫy dài một mét .đặt ở đâu để có thể dùng 3600n có thể nâng tảng đá nặng 120kg?
Bài 4: Tìm x, biết:
a) 3(2x – 3) + 2(2 – x) = –3 ; b) x(5 – 2x) + 2x(x – 1) = 13 ;
c) 5x(x – 1) – (x + 2)(5x – 7) = 6 ; d) 3x(2x + 3) – (2x + 5)(3x – 2) = 8 ;
e) 2(5x – 8) – 3(4x – 5) = 4(3x – 4) + 11; f) 2x(6x – 2x 2 ) + 3x 2 (x – 4) = 8.
\(a,3\left(2x-3\right)+2\left(2-x\right)=-3\\ \Leftrightarrow6x-9+4-2x=-3\\ \Leftrightarrow4x=2\\ \Leftrightarrow x=\dfrac{1}{2}\\ b,x\left(5-2x\right)+2x\left(x-1\right)=13\\ \Leftrightarrow5x-2x^2+2x^2-2x=13\\ \Leftrightarrow3x=13\\ \Leftrightarrow x=\dfrac{13}{3}\\ c,5x\left(x-1\right)-\left(x+2\right)\left(5x-7\right)=6\\ \Leftrightarrow5x^2-5x-5x^2-3x+14=6\\ \Leftrightarrow-8x=-8\\ \Leftrightarrow x=1\\ d,3x\left(2x+3\right)-\left(2x+5\right)\left(3x-2\right)=8\\ \Leftrightarrow6x^2+9x-6x^2-11x+10=8\\ \Leftrightarrow-2x=-2\\ \Leftrightarrow x=1\)
\(e,2\left(5x-8\right)-3\left(4x-5\right)=4\left(3x-4\right)+11\\ \Leftrightarrow10x-16-12x+15=12x-16+11\\ \Leftrightarrow-14x=-4\\ \Leftrightarrow x=\dfrac{2}{7}\\ f,2x\left(6x-2x^2\right)+3x^2\left(x-4\right)=8\\ \Leftrightarrow12x^2-4x^3+3x^3-12x^2=8\\ \Leftrightarrow-x^3-8=0\\ \Leftrightarrow-\left(x^3+8\right)=0\\ \Leftrightarrow-\left(x+2\right)\left(x^2-2x+4\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=-2\\x\in\varnothing\left(x^2-2x+4=\left(x-1\right)^2+3>0\right)\end{matrix}\right.\)
Bài 4:
a: Ta có: \(3\left(2x-3\right)-2\left(x-2\right)=-3\)
\(\Leftrightarrow6x-9-2x+4=-3\)
\(\Leftrightarrow4x=2\)
hay \(x=\dfrac{1}{2}\)
b: Ta có: \(x\left(5-2x\right)+2x\left(x-1\right)=13\)
\(\Leftrightarrow5x-2x^2+2x^2-2x=13\)
\(\Leftrightarrow3x=13\)
hay \(x=\dfrac{13}{3}\)
c: Ta có: \(5x\left(x-1\right)-\left(x+2\right)\left(5x-7\right)=6\)
\(\Leftrightarrow5x^2-5x-5x^2+7x-10x+14=6\)
\(\Leftrightarrow-8x=-8\)
hay x=1
a/ \(3\left(2x-3\right)+2\left(2-x\right)=-3\)
\(\Leftrightarrow6x-9+4-2x=-3\)
\(\Leftrightarrow4x=2\)
\(\Leftrightarrow x=\dfrac{1}{2}\)
Vậy: \(x=\dfrac{1}{2}\)
===========
b/ \(x\left(5-2x\right)+2x\left(x-1\right)=13\)
\(\Leftrightarrow5x-2x^2+2x^2-2x=13\)
\(\Leftrightarrow3x=13\)
\(\Leftrightarrow x=\dfrac{13}{3}\)
Vậy: \(x=\dfrac{13}{3}\)
==========
c/ \(5x\left(x-1\right)-\left(x+2\right)\left(5x-7\right)=6\)
\(\Leftrightarrow5x^2-5x-5x^2+7x-10x+14=6\)
\(\Leftrightarrow-8x=-8\)
\(\Leftrightarrow x=1\)
Vậy: \(x=1\)
==========
d/ \(3x\left(2x+3\right)-\left(2x+5\right)\left(3x-2\right)=8\)
\(\Leftrightarrow6x^2+9x-6x^2+4x-15x+10=8\)
\(\Leftrightarrow-2x=-2\)
\(\Leftrightarrow x=1\)
Vậy: \(x=1\)
==========
e/ \(2\left(5x-8\right)-3\left(4x-5\right)=4\left(3x-4\right)+11\)
\(\Leftrightarrow10x-16-12x+15=12x-16+11\)
\(\Leftrightarrow-14x=-4\)
\(\Leftrightarrow x=\dfrac{2}{7}\)
Vậy: \(x=\dfrac{2}{7}\)
==========
f/ \(2x\left(6x-2x^2\right)+3x^2\left(x-4\right)=8\)
\(\Leftrightarrow12x^2-4x^3+3x^3-12x^2=8\)
\(\Leftrightarrow-x^3=8\)
\(\Leftrightarrow x=-2\)
Vậy: \(x=-2\)
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
Tìm x biết:
a) 4(18-5x) - 12(3x-7) = 15(2x-16) - 6(x+14)
b) 5(3x+5) - 4(2x-3) = 5x+3(2x+12)+1
c)2(5x-8) - 3(4x-5) = 4(3x-4) + 11
d) 5x-3 {4x-2 [4x-3(5x-2)]}=182
3,26 + 4/5 =?
làm nhanh lên giúp mình nhé
3,26+4/5=3,26+0,8=3,34
K cho mình cái
\(2\left(5x-8\right)-3\left(4x-5\right)=4\left(3x-4\right)+11\)
\(\Leftrightarrow10x-16-12x+15=12x+16+11\)
\(\Leftrightarrow-2x-1=12x+27\Leftrightarrow-14x-28=0\Leftrightarrow x=-2\)