Question

Simplify (9x^3+2x^2-5x+4)-(5x^3-7x+4)

Answer 1

`=9x^(3) +2x^(2) -5x+4-5x^(3) +7x-4\\=9x^(3) -5x^(3) +2x^(2) -5x+7x+4-4\\=4x^(3) +2x^(2) +2x`

Be remined for the second expression affects the signs of all the terms inside the brackets.