Tìm x
a, ( 2x - 3)2 = ( 2x - 3) ( x + 1)
b, x.( 2x - 9) = 2x.( x - 5)
c, 7 - 9x = 7x + 23
d, ( 2x + 5).( x - 3) = 0
tìm x
a) (x+2)(x+3)-(x-2)(x+5)=6
b) (3x+2)(2x+9)-(x+2)(6x+1)=(x+1)-(x-6)
c) 3(2x-1)(3x-1)-(2x-3)(9x-1)=0
a: Ta có: \(\left(x+2\right)\left(x+3\right)-\left(x-2\right)\left(x+5\right)=6\)
\(\Leftrightarrow x^2+5x+6-x^2-3x+10=6\)
\(\Leftrightarrow2x=-10\)
hay x=-5
b: Ta có: \(\left(3x+2\right)\left(2x+9\right)-\left(x+2\right)\left(6x+1\right)=\left(x+1\right)-\left(x-6\right)\)
\(\Leftrightarrow6x^2+27x+4x+18-6x^2-x-12x-2=x+1-x+6\)
\(\Leftrightarrow18x+16=7\)
hay \(x=-\dfrac{1}{2}\)
c: Ta có: \(3\left(2x-1\right)\left(3x-1\right)-\left(2x-3\right)\left(9x-1\right)=0\)
\(\Leftrightarrow3\left(6x^2-2x-3x+1\right)-\left(18x^2-2x-27x+3\right)=0\)
\(\Leftrightarrow18x^2-15x+3-18x^2+27x-3=0\)
hay x=0
Tìm x biết:
a)(2x-3)-(x-5)=(x+7)-(x+2)
b)(7x-5)-(6x+4)+(2x+3)-(2x+1)
c)(9x-3)-(8x+5)=(3x+2)
d)(x+7)-(2x+3)=(3x+5)-(2x+4)
a) ( 2x - 3 ) - ( x - 5 ) = ( x + 7 ) - ( x + 2 )
<=> 2x - 3 - x + 5 = x + 7 - x - 2
<=> x = 3
b)(7x-5)-(6x+4)=(2x+3)-(2x+1)
<=> 7x - 5 - 6x - 4 = 2x + 3 - 2x - 1
<=> x = 11
c)(9x-3)-(8x+5)=(3x+2)
<=> 9x - 3 - 8x - 5 = 3x + 2
<=> -2x = 10
<=> x = -5
d)(x+7)-(2x+3)=(3x+5)-(2x+4)
<=> x + 7 - 2x - 3 = 3x + 5 - 2x - 4
<=> -2x = -3
<=> x = 3/2
ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠᅠ ᅠ
giải phương trình
a, \(\sqrt{4x-20}+3\sqrt{\dfrac{x-5}{9}}-\dfrac{1}{3}\sqrt{9x-45}=4\)
b, \(2x-x^2+\sqrt{6x^2-12x+7}=0\)
c, \(\dfrac{9x-7}{\sqrt{7x+5}}=\sqrt{7x+5}\)
Tìm x
a.(x+2).(x+3)-(x-2).(x+5) = 0
b. (2x+3).(x-4)+(x-5)(x+2) = (3x-5)(x-4)
c. (3x+2)(2x+9)-(x+2)(6x+1) = x+1-(x-6)
d. 3( 2x-1).(3x-1)-(2x-3).(9x-1)=0
(x+2)(x+3)-(x-2)(x+5)=0
=> x2+5x+6-x2-3x+10=0
=>2x+16=0
=>2x=-16
=>x=-8
Giai cac phuong trinh sau
1) (5x-4).(4x+6) = 0
2) (4x-10).(24+5x) = 0
3) (x-3).(2x+1) = 0
4) (2x+1).(x2+2) = 0
5) (x2+4).(7x-3) = 0
6) (x-5).(3-2x).(3x+4) = 0
7) (x-2).(3x+5) = (2x-4).(x+1)
8) (2x+5).(x-4) = (x-5).(4-x)
9) 9x2-1 = (3x+1).(2x-3)
10) (2x-1)2 = 49
11) (5x-3)2 - (4x-7)2 = 0
12) (2x+7)2 = 9.(x+2)2
Giúp mình giải gấp .Cám ơn
1) \(\left(5x-4\right)\left(4x+6\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}5x-4=0\\4x-6=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}5x=4\\4x=6\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{4}{5}\\x=\dfrac{3}{2}\end{matrix}\right.\)
Vậy phương trình có tập nghiệm S = \(\left\{\dfrac{4}{5};\dfrac{3}{2}\right\}\)
2) \(\left(4x-10\right)\left(24+5x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}4x-10=0\\24+5x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}4x=10\\5x=-24\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{5}{2}\\x=\dfrac{-24}{5}\end{matrix}\right.\)
Vậy phương trình có tập nghiệm S = \(\left\{\dfrac{5}{2};\dfrac{-24}{5}\right\}\)
3) \(\left(x-3\right)\left(2x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-3=0\\2x+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\2x=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=\dfrac{-1}{2}\end{matrix}\right.\)
Vậy phương trình có tập nghiệm S = \(\left\{3;\dfrac{-1}{2}\right\}\)
I) THỰC HIỆN PHÉP TÍNH a) 2x(x^2-4y) b)3x^2(x+3y) c) -1/2x^2(x-3) d) (x+6)(2x-7)+x e) (x-5)(2x+3)+x II phân tích đa thức thành nhân tử a) 6x^2+3xy b) 8x^2-10xy c) 3x(x-1)-y(1-x) d) x^2-2xy+y^2-64 e) 2x^2+3x-5 f) 16x-5x^2-3 g) x^2-5x-6 IIITÌM X BIẾT a)2x+1=0 b) -3x-5=0 c) -6x+7=0 d)(x+6)(2x+1)=0 e)2x^2+7x+3=0 f) (2x-3)(2x+1)=0 g) 2x(x-5)-x(3+2x)=26 h) 5x(x-1)=x-1 IV TÌM GTNN,GTLN. a) tìm giá trị nhỏ nhất x^2-6x+10 2x^2-6x b) tìm giá trị lớn nhất 4x-x^2-5 4x-x^2+3
Giải như sau.
(1)+(2)⇔x2−2x+1+√x2−2x+5=y2+√y2+4⇔(x2−2x+5)+√x2−2x+5=y2+4+√y2+4⇔√y2+4=√x2−2x+5⇒x=3y(1)+(2)⇔x2−2x+1+x2−2x+5=y2+y2+4⇔(x2−2x+5)+x2−2x+5=y2+4+y2+4⇔y2+4=x2−2x+5⇒x=3y
⇔√y2+4=√x2−2x+5⇔y2+4=x2−2x+5, chỗ này do hàm số f(x)=t2+tf(x)=t2+t đồng biến ∀t≥0∀t≥0
Công việc còn lại là của bạn !
\(\left(x+6\right)\left(2x+1\right)=0\)
<=> \(\orbr{\begin{cases}x+6=0\\2x+1=0\end{cases}}\)
<=> \(\orbr{\begin{cases}x=-6\\x=-\frac{1}{2}\end{cases}}\)
Vậy....
hk tốt
^^
Giúp mình với
a)3y-2y=2y-3
b)3-4x+24+6x=x+27+3x
c)5-(6-x)=4(3-2x)
d)4(x+3)=-7x+17
e)11x+42-2x=100-9x-22
g)2x+3/3 =5-4x/2
f)5x+3/12 = 1+2x/9
h)7x-1/6 = 16-x/5
i)x-3/5 = 6-1-2x/3
k)3x-2/6 - 5=3-2(x+7)/4
3x-7/2 + x+1/3=-16
x-x+1/3 = 2x+1/5
2x-1/3 - 5x+2/7
a, 3y-2y=2y-3
3y-2y-2y=3
-y=3
y=-3
b, 3-4x+24+6x=x+27+3x
-4x+6x-x-3x =27-3-24
-2x =0
x =0
c, 5-(6-x)=4.(3-2x)
5-6+x =12-8x
x+8x =12+6-5
9x =13
x =13/9
d, 4.(x+3)=-7x+17
4x+12 =-7x+17
4x+7x =17-12
11x =5
x =5/11
A) \(3y-2y=2y-3\) \(\Leftrightarrow y-2y=-3\) \(\Leftrightarrow y=3\)
B) \(3-4x+24+6x=x+27-3x\)\(\Leftrightarrow3-4x+24+6x-x-27-3x=0\)
\(\Leftrightarrow-2x=0\)\(\Leftrightarrow x=0\)
C) \(5-\left(6-x\right)=4\left(3-2x\right)\)\(\Leftrightarrow5-6x+x-12+8x=0\)\(\Leftrightarrow9x-13=0\)\(\Leftrightarrow x=\frac{13}{9}\)
D) \(4\left(x+3\right)=-7x+17\) \(\Leftrightarrow4x+12+7x-17=0\)\(\Leftrightarrow11x-5=0\)\(\Leftrightarrow x=\frac{5}{11}\)
E) \(11x+42-2x=100-9x-22\)\(\Leftrightarrow11x+42-2x-100+9x+22=0\)
\(\Leftrightarrow18x-36=0\)\(\Leftrightarrow x=2\)
F) \(5x+\frac{3}{12}=1+\frac{2x}{9}\)\(\Leftrightarrow180x+9-36-8x=0\)\(\Leftrightarrow172x-27=0\)\(\Leftrightarrow x=\frac{27}{172}\)
TK nka !!! Mk giải tiếp !!
Giúp mình với
a)3y-2y=2y-3
b)3-4x+24+6x=x+27+3x
c)5-(6-x)=4(3-2x)
d)4(x+3)=-7x+17
e)11x+42-2x=100-9x-22
g)2x+3/3 =5-4x/2
f)5x+3/12 = 1+2x/9
h)7x-1/6 = 16-x/5
i)x-3/5 = 6-1-2x/3
k)3x-2/6 - 5=3-2(x+7)/4
3x-7/2 + x+1/3=-16
x-x+1/3 = 2x+1/5
2x-1/3 - 5x+2/7
Tìm x:
a) (x-20) mũ 2 -(x+1)(x+3)=-7
b) (3x+5)(4-3x)=0
c) x mũ 3 -9x=0
d)2/3x (x mũ 2 -4)=0
e) (2x+1)-x(2x+1)=0
f)(2x-1) mũ 2 -(2x+5) (2x-5) =18
g)x mũ 2 -25 =6x-9