Idon’t know how to solve c and d.
i’m supposed to use the quadratic formula.

Step-by-step explanation:

It is much easier to use the square root method but since you requested the quadratic formula, I will solve it using that method.

First, replace g(x) with 0 for letter c and 11 for letter d. Then simplify and move everything to one side so the equation is equal to zero.  Then plug in the a, b, and c values into the quadratic formula to solve for x.

g(x) + 5 = 2x² - 8

c) 0 + 5 = 2x² - 8

    0       = 2x² - 13     (subtracted 5 from both sides)

-->      0 = 2x² + 0x - 13         --> a = 2, b = 0, c = -13

d) 11 + 5 = 2x² - 8

    0       = 2x² - 24     (subtracted 16 from both sides)

-->      0 = 2x² + 0x - 24         --> a = 2, b = 0, c = -24