Question

using remainder theorm show that (x-5) is factor of X3-3X2-4X-30​

Answer 1

f(x) = x³-3x²-4x-30

x-5 = 0

x-5 = 0

x = 5

f(5) = 5³ - 3×5²-4×5 - 30

= 125 - 3× 25 - 20 -30

= 125 - 75 - 50

= 50-50 = 0

Hence proved that x-5 is a factor of x³-3x²-4x-30

Hope it helps you