1.Rút gọn biểu thức
a) (x+1) ² - (x-1) ²-3(x+1)(x-1)
b) 5(x+2)(x-2)-(2x-3) ² -x ² +17
c) (x-1) ³ - (x-1)(x ² + x + 1 )
d) (x-3) ³ - (x-3)(x ² + 3x + 9) + 6(x+1) ²
2. Tìm x
a) 5(x-1)=x-1
b) (2x+1) ² =9
c) (2x-3) ² - (x+5) ² = 0
d) (1-3x) ² - (4-2x) ²=0
e)x(x-5)(x+5)-(x+2)(x ²-2x+4)=17
f)x(5-2x)+2x(x-1)=13
g)2x(x ² - 2) + (x ² - 1)(1-2x)-x ²= -12
h)2x(3x-1)(2x+5)-6(2x-1)(x+2)=-6
i)(x-1)(x ² + x + 1)+x(x+2)(2-x)=5
j)(5x+1) ² - (5x-3)(5x+3)=30
Loga
Sinh Học lớp 12
