Question

21. Find the coefficient of x and x^2 in the product of (x -3)(x+7)(x-4)​

Answer 1

Answer:

(x - 3) (x + 7) (x - 4)

x( x + 7 ) - 3 ( x + 7)

x² + 7x - 3x - 21

(x² + 4x - 21) ( x- 4 )

x (x² + 4x - 21 ) - 4 ( x² + 4x - 21 )

x³ + 4x² - 2x - 4x² - 16x + 84

x³ -18x + 84

Co efficient of x = -18

Co efficient of x² = 0