What are the zeros of the quadratic function f(x) = 8x2 – 16x – 15?

Question

What are the zeros of the quadratic function f(x) = 8x² – 16x – 15?

x = –1 –  and x = –1 + 

x = –1 –  and x = –1 + 

x = 1 –  and x = 1 + 

x = 1 –  and x = 1 + 

Answer 1

8x^2 - 16x - 15

x^2 - 2x -15/8 = 0

x^2 -2x + 1 = 15/8 + 1

(x-1)^2 = 31/8

x-1 = + or - sqr(31/8) which is about the sqr 4= 2

x = 1 + or - sqr(31/8) = about 1 + or - 1.97 = 2.97 or - .97 = about 3 or - 1

None of the 4 alternatives given are close.

closest might be 2nd to last, but it's off too much too