Question

If a + c = b, then a zero of the polynomial ax² + bx + c, is ______.

Answer 1

If a + c = b, then a zero of the polynomial ax² + bx + c, is –1.

Explanation:

With b = a + c, evaluate at x = –1: 

a(–1)² + b(–1) + c = a – b + c 

= a – (a + c) + c

= 0

So x = –1 is a root.