Question

If (x+1) is a factor of 2x^2 +2ax + 5x + 10. Find a

Answer 1

x+1=0

x=-1

f(x)=2x^2+2ax+5x+10

f(-1)=2(-1)^2+2a(-1)+5(-1)+10

2(1)-2a-5+10=0

-2a+7=0

-2a=-7

a=7/2

Answer 2

If (x+1)is a factor then -1 is the zeroes of the given polynomial.Then

2x^2+2ax+5x+10=0

2(-1)^2+2a(-1)+5(-1)+10=0

2-2a-5+10=0

-2a+7=0

2a=7

a=7/2

I hope this answer will helps you.