Solve the quadratic equation.

Question

x2 + 9x − 36 = 0

a. x = 3 or 12
b. x = 3 or −12
c. x = 6 or −6
d. no real solution

Answer 1

To solve the quadratic equation x^2 + 9x - 36 = 0, we can factor it or use the quadratic formula. Let's use the quadratic formula:

The quadratic formula is x = (-b ± √(b^2 - 4ac)) / (2a)

In this equation, a = 1, b = 9, and c = -36.

Plugging these values into the quadratic formula, we get:
x = (-(9) ± √((9)^2 - 4(1)(-36))) / (2(1))
x = (-9 ± √(81 + 144)) / 2
x = (-9 ± √(225)) / 2
x = (-9 ± 15) / 2
x = (6/2) or (-24/2)
x = 3 or -12

Therefore, the correct answer is:
b. x = 3 or −12