Question

Select the correct answer.

Simplify the polynomial expression.
3x(-2x + 7) - 5(x - 1)(4x - 3)
OA. -26x2 + 56x - 15
B.
14x214x + 15
OC. -26x2 + 21x - 15
OD. -2x2 + 14x - 2

Answer 1

Simplifying Polynomial Expressions

To simplify a polynomial expression, we can expand parentheses by multiplying the terms within with the coefficient outside of them and add like terms.

Solving the Question

`3x(-2x + 7) - 5(x - 1)(4x - 3)`

⇒ Open up the parentheses

`=(3x*(-2x) + 3x*7) - 5(x(4x - 3)-1(4x-3))\\=(-6x^2 + 21x) - 5(4x^2 - 3x-4x+3)\\=-6x^2 + 21x - 5(4x^2 - 7x+3)=-6x^2 + 21x - (20x^2 - 35x+15)\\=-6x^2 + 21x - 20x^2 + 35x-15\\=- 26x^2 + 56x-15`

Answer

`- 26x^2 + 56x-15`