\(\Rightarrow x^2-16-x^2+3x=5\)
\(\Rightarrow3x=21\Rightarrow x=7\)
=> Chọn A
\(\Rightarrow x^2-16-x^2+3x=5\)
\(\Rightarrow3x=21\Rightarrow x=7\)
=> Chọn A
Câu 4.Tìm x, biết 5x(x − 3) − 5x\(^2\) = 45
A. x = 0
B. x = 1
C .x = −3
D. x = 2
Tìm x biết :
a) \(\left(x-2\right)^3+6\left(x+1\right)^2-x^3+12=0\)
b) \(\left(x-5\right)\left(x+5\right)-\left(x+3\right)^3+3\left(x-2\right)^2=\left(x+1\right)^2-\left(x+4\right)\left(x-4\right)+3x^2\)
c) \(\left(2x+3\right)^2+\left(x-1\right)\left(x+1\right)=5\left(x+2\right)^2-\left(x-5\right)\left(x+1\right)+\left(x+4\right)^2\)
d) \(\left(1-3x\right)^2-\left(x-2\right)\left(9x+1\right)=\left(3x-4\right)\left(3x+4\right)-9\left(x+3\right)^2\)
Tìm x, biết:
a) (2x+3)(x-4)+(x-5)(x-2)=(3x-5)(x-4)
b) (8x-3)(3x+2)-(4x+7)(x+4)=(2x+1)(5x-1)
19 Tìm x, biết
a) (x+2)(x+3)-(x-2)(x+5)=0 ; b) (2x+3)(x-4)+(x-5)(x-2)=(3x-5)(x-4)
c) (8-4x)(x+2)+4(x-2)(x+1)=0 ; d) (2x-3)(8x+2)=(4x+1)(4x-1)-3
a) 4x(x-5)-7x(x-4)+3x2=12
b)-3x(x-5)+5(x-1)+3x2=4-x
c)(x-5)(x-4)-(x+1)(x-2)=7
d)-(x+3)(x-4)+(x-1)(x+1)=10
e)(x-3)(x2+3x+9)+x(5-x2)=6x
1. Tìm x biết:
a. ( 8x - 3 ).( 3x + 2 ) - ( 4x + 7 ).( x + 4 ) = ( 2x + 1 ).( 5x - 1 )
b. 4.( x - 1 ).(x + 5 ) - ( x + 2 ).( x + 5 ) = 3.( x - 1 ).( x + 2 )
Tìm x, biết:
a) ( x - 5)(x + 5) - ( x- 3)2 + 3( x - 2)2 = ( x + 1)2 - ( x+4)( x - 4) + 3x2
b) ( 2x + 3)2 + ( x - 1)( x + 1) = 5( x + 2)2 - ( x - 5)( x + 1) + ( x + 4)2
Bài 1: Áp dụng những hằng đẳng thức để tìm x
a) -(x+3)(x-4)+(x+1)(x-1)=10
b) (2x-1)(x-2)-(x+3)(2x-7)=3
c) (x-5)(4-x)-(x-1)(x+3)=-2x
d) 3(x+7)(x-7)-(x-1)(3x+2)=13
e) 5(x-3)(x-7)-(5x+1)(x-2)=8
f) (3x-4)(x-2)=3x(x-9)-10
g) 5x(x-3)=(x-2)(5x-1)-5
h) 6(x-3)(x-4)-6x(x-2)=4
i) (x-2)(x+3)-(x+4)(x-7)=5-x
k) (4x-5)(x+1)-4(x-1)(x+1)=7
l) (3x-4)(x-2)=3x(x-9)-3