Question

if 3 is a zero zero of the polynomial x²+2x-a find the value of 'a' and other other zero

Answer 1

3×3+2×3-a
9+6-a
15-a
But 3 is a factor, so
15-a=0
a=15

Answer 2

Hi ,

Let p ( x ) = x² + 2x - a

If 3 is the zero of the polynomial p(x)

then

p ( 3 ) = 0

3² + 2 × 3 - a = 0

9 + 6 - a = 0

15 - a = 0

-a = -15

a = 15

I hope this helps you.

:)