Question

1.rút gọn bt A= (x+2)³-2x(x+3)+(x³-8):(x-2)

2. tìm x biết:

a. 3x²-12x=0

b.4x²-1-4(1-2x)=0

Answer 1

ảnh lỗi r ạ

Answer 2

Lỗi rùi

Answer 3

lưu ảnh rồi gửi vào đây nhé

Answer 4

\(1,A=x^3+6x^2+12x+8-2x^2-6x+\left(x-2\right)\left(x^2+2x+4\right):\left(x-2\right)\\ A=x^3+4x^2+6x+8+x^2+2x+4\\ A=x^3+5x^2+8x+12\\ 2,\\ a,\Leftrightarrow3x\left(x-4\right)=0\Leftrightarrow\left[{}\begin{matrix}x=0\\x=4\end{matrix}\right.\\ b,\Leftrightarrow\left(2x-1\right)\left(2x+1\right)+4\left(2x-1\right)=0\\ \Leftrightarrow\left(2x-1\right)\left(2x+5\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=-\dfrac{5}{2}\end{matrix}\right.\)