Question

A rectangle is (2 x + 5) long and (x^2 - 3x + 1) wide. What is its area?

Answer 1

Area of a rectangle is computed by multiplying its length and its width.

A = L * W
A = (2x+5)(x²-3x+1)
A = 2x(x²) + 2x(-3x) + 2x(1) + 5(x²) + 5(-3x) + 5(1)
A = 2x³ - 6x² + 2x + 5x² - 15x + 5
Group like terms:
A = 2x³ - 6x² + 5x² + 2x - 15x + 5
A = 2x³ - x² - 13x + 5   CHOICE A.