Question

F(x)=2x^2+16x-7 in vertex form

Answer 1

y=2(x+4)^2−39

Explanation:

Based on my calculation that´s the answer :-)

Answer 2

f(x) = 2 ( x² + 8x ) - 7

= 2 [(x + 4)² - 4²] - 7

= 2 (x + 4)² - 32 - 7

= 2 (x + 4)² - 39

(x+4)² = x² + 2*x*4 + 4² = x² + 8x + 4²

it's why

x² + 8x = (x + 4)² - 4²