Answer:
Step-by-step explanation:
f(x) = x³ + 2x² - 7x - 8
g(x) = -4x - 7
h(x) = 4x² - x - 15
k(x) = -x² + 7x + 4
a) h(x) - k(x) = 4x² - x - 15 - [-x² + 7x + 4]
= 4x² - x - 15 + x² - 7x - 4
= <u>4x² + x²</u> <u>- x - 7x</u> <u> - 15 - 4</u>
= 5x² - 8x - 19
b) f(x) - h(x) = x³ + 2x² - 7x - 8 -[ 4x² - x - 15 ]
= x³ + 2x² - 7x - 8 - 4x² + x + 15
= x³ + <u>2x² - 4x² </u> <u>-7x + x</u> <u>-8 + 15</u>
= x³ - 2x² - 6x + 7
c) f(x) - g(x) = x³ + 2x² - 7x - 8 - [ -4x - 7 ]
=x³ + 2x² - 7x - 8 + 4x + 7
= x³ + 2x² - 7x + 4x - 8 + 7
= x³ + 2x² - 3x - 1
d) k(x) - f(x) = -x² + 7x + 4 - [ x³ + 2x² - 7x - 8]
= -x² + 7x + 4 - x³ - 2x² + 7x + 8
= -x² -2x² + 7x + 7x + 4 + 8 - x³
= -3x² + 14x + 12 - x³
= -x³ - 3x² + 14x + 12
