Question

Find the coefficient of x2 in ( 4+ 4x2)( 3x2–5).

Answer 1

- 8

Explanation:

Given

(4 +4 x²)(3x² - 5)

Each term in the second factor is multiplied by each term in the first factor, that is

4(3x² - 5) + 4x²(3x² - 5) ← distribute parenthesis

= 12x² - 20 + 12
`x^(4)` - 20x² ← collect like terms

= 12
`x^(4)` - 8x² - 20

with coefficient of x² term being - 8