Question

Answer 1

Bài 2:

(3x+2)(3x-2)-9x(x-1)=4

=>\(9x^2-4-9x^2+9x=4\)

=>9x-4=4

=>9x=8

=>\(x=\frac89\)

Bài 1:

a; \(2x\left(x^2-4x+1\right)\)

\(=2x\cdot x^2-2x\cdot4x+2x\cdot1\)

\(=2x^3-8x^2+2x\)

b: \(\left(16x^5y^4-8x^4y^3\right):4x^2y^2+2x^2y\)

\(=4x^3y^2-2x^2y+2x^2y=4x^3y^2\)

c: \(\frac{x+2}{x}+\frac{5-x}{x+2}\)

\(=\frac{\left(x+2\right)^2+x\left(5-x\right)}{x\left(x+2\right)}\)

\(=\frac{x^2+4x+4+5x-x^2}{x\cdot\left(x+2\right)}=\frac{9x+4}{x\left(x+2\right)}\)