Answer:
+ 80
Step-by-step explanation:
Given
(2 - x)(5 - 3x)(1 - 7x) ← expand the first two factors using FOIL
= (10 - 11x + 3x²)(1 - 7x)
Each term in the second factor is multiplied by each term in the first factor
= 10(1 - 7x) - 11x(1 - 7x) + 3x²(1 - 7x) ← distribute the 3 parenthesis
= 10 - 70x - 11x + 77x² + 3x² - 21x³ ← collect like terms
= - 21x³ + 80x² - 81x + 10
The coefficient of the x² term is + 80
