Question

What are the zeros of the function y = x2 + 10x – 171, and why?

A) The zeros are x = –19 and x = 9 because in factored form, the function is y = (x – 19)(x + 9).
B) The zeros are x = –19 and x = 9 because in factored form, the function is y = (x + 19)(x – 9).
C) The zeros are x = 19 and x = –9 because in factored form, the function is y = (x – 19)(x + 9).
D) The zeros are x = 19 and x = –9 because in factored form, the function is y = (x + 19)(x – 9).

Answer 1

Hello,

Answer B

y=x²+10x-171=x²-9x+19x-171=x(x-9)+19(x-9)=(x-9)(x+19)

Answer 2

Y = x^2 + 10x - 171
y = (x - 9)(x + 19)

x - 9= 0 x + 19 = 0
x = 9 x = -19

Answer B covers all requirements... the factored form is
y= (x + 19)(x - 9)
and the zeros are -19 and 9