Question

if ×-3 is a factor of ׳+aײ+b×+18 and a+b =-7 find a and b ​

Answer 1

Answer:

x-3=0

x=3

p(x)=x³-ax²+bx+18

p(3)=(3)³-a(3)²+b(3)+18

27-a(9)+3b+18=0

-9a+3b+45=0

3(-3a+b+15)=0

-3a+b+15=0/3

3a-b-15=0

3a-b=15———eq-1

a+b=-7———eq-2

From eq-1 & eq-2

3a-b=15

+ a+b=-7

—————

4a=8

a=8/4

→a=2

substitute a=2 in eq-1

3(2)-b=15

6-b=15

6-15=b

→b=-9