Answer: y=(x+7)^2-9 where h=-7 and k=-9
Explanation:
We need to "complete the square",
A perfect square trinomial formule is:
(a+b)^{2}=a+2ab+b^{2}
in this case, a is x and to find -h we know that 14x is 2*x*(-h) so:
14x=2*x*(-h)
14x/2x=-h (x is simplified)
7=-h => h=-7
we add +7^2 and -7^2, to the first equation:
y= x^2 + 14x + 7^2 -7^2 + 40 (the underlined section is a perfect square trinomial already)
y=(x+7)^2 -49 +40 (addition)
y= (x+7)^2 - 9