Áp dụng hằng đẳng thức, ta cần tìm x sao cho:
\(x^2+6x-1=5\Leftrightarrow x^2+6x-6=0\Leftrightarrow\left[{}\begin{matrix}x=-3+\sqrt{15}\\x=-3-\sqrt{15}\end{matrix}\right.\)
Vậy...
1.(x+2)3+(x-3)2-x2(x+5)
2.(2x+3).(x-5)+2x(3-x)+x-10
3.(x+5).(x2-5x+25)-x(x-4)2+16x
4.(-x-2)3+(2x-4).(x2+2x+4)-x2.(x-6)
tìm x biết:
a) (x-3)2-4=0
b) x2-2x=24
c) (x+4)2-(x+1)(x-1)=16
d) (2x+1)2-4(x-1)2=9
e) (x+3)2-(x-4)(x+8)=1
f) (2x-1)2+(x+3)2-5(x+7)(x-7)=0
g) 3(x+2)2+(2x-1)2-7(x+3)(x-3)=36
1.(x+2)3+(x-3)2-x2(x+5)
2.(2x+3).(x-5)+2x(3-x)+x-10
3.(-x-2)3+(2x-4).(x2+2x+4)-x2.(x-6)
Bài 1: Thu gọn các biểu thức sau
a)(2x2 + 5x - 2)(2x2 - 4x +3)
b)(2x -3)(3x - 2) - 3x(2x - 5)
c)(x -1)(x2 + x + 1) - (x + 1)(x2 - x +1)
d)(x2 + x - 1)(x2 - x + 1)
e)(2 + 3y)2 - (2x -3y)2 -12xy
d)(x2 - 4x)(5 + 2x - x2)
cảm ơn!giúp mình với chiều nay ktra 15ph T_T
Tìm x biết
b) ( 2x + 3)^2 – (2x + 1)(2x – 1) = 22
c) ( 4x + 3)( 4x – 3) – (4x -5)^2 = 16 d) x^3 – 9x^2+ 27x – 27 = - 8
e) (x + 1)^3 – x2 (x + 3) = 2 ; f) (x – 2)^3 – x( x – 1)(x + 1) + 6x2 =5
Tìm x biết
1.x(x+1)-x2+1=0
2.4x.(x-2)-6+3x=0
3.x(x+2)-3(x+2)=0
thu gọn biểu thức
a) (6x-2)2+4(3x-1)(2+y)+(y+2)2-(6x+y)2
b)5(2x-1)2+2(x-1)(x+3)-2(5-2x)2-2x(7x+12)
c)2(5x-1)(x2-5x+1)+(x2-5x+1)2+(5x-1)2-(x2-1)(x2+1)
d)(x2+4)2-(x2+4)(x2-4)(x2+16)-8(x-4)(x+4)
Tìm x biết :
a, \(\left(x-1\right)^2-\left(x+3\right)\left(x-3\right)=5\)
b, \(\left(x+3\right)^2-x\left(x-1\right)=6\)
c, \(\left(x-1\right)\left(x^2+x+1\right)+\left(2x\right)\left(4-2x+x2\right)=5-x\)
Thực hiện phép tính :
1.(2x+3).(x-5)+2x(3-x)+x-10
2.(-x-2)3+(2x-4).(x2+2x+4)-x2.(x-6)
