Question

Answer 1

a: \(=9x^2-12x+4+5\left(1-x^2\right)\)

\(=9x^2-12x+4+5-5x^2=4x^2-12x+9\)

b: \(=\dfrac{x^2+x-6-\left(2x-1\right)\left(x+2\right)-x+3}{\left(x-2\right)\left(x+2\right)}\)

\(=\dfrac{x^2-3-2x^2-4x+x+2}{\left(x-2\right)\left(x+2\right)}\)

\(=\dfrac{-x^2-3x+1}{\left(x-2\right)\left(x+2\right)}\)

c: \(=\dfrac{6x^3+3x^2-10x^2-5x+6x+3}{2x+1}=3x^2-5x+2\)