b.)x³-7x²+3x+36
(x-4)(x²-3x-9)
Distribute x and -4 to x²-3x-9
=x²(x)-3x(x)-9(x)+x²(-4)-3x(-4)-9(-4)
=x³-3x²-9x-4x²+12x+36
Combine all liked terms
=x³-7x²+3x+36
abcb
Step-by-step explanation: