Question

if the expression 4x3- 12x2 +ax + b has x-3 as a factor and when it is divided by x+2 the remainder is -75 find a and b​

Answer 1

Step-by-step explanation:

4x³-12x²+ax+b has x-3 as a factor means

4.3³-12.3²+3a+b=0

or 108-108+3a+b=0

or 3a+b=0

or 3a=-b

it is divided by x+2 the remainder is -75 means

4.2³-12.2²+2a+b+75=0

or 32-48+2a+b+75=0

or 2a+b+59=0

or 2a-3a+59=0

or a=59

b=177