X^2+12x=-36 solve for x

x = - 6 (multiplicity 2)

Step-by-step explanation:

x^2 + 12x = - 16.

Rearranging:-

x^2 + 12x + 36 = 0

We can factor this. Note + 36 = + 6 * + 6.

So (x + 6) (x + 6) = 0

x = - 6 (multiplicity 2).

x = - 6

Step-by-step explanation:

rearrange into standard form : ax² + bx + c = 0 : a ≠ 0

add 36 to both sides

x² + 12x + 36 = 0 ← in standard form

(x + 6) (x + 6) = 0 ← in factored form

(x + 6) ² = 0, hence

x + 6 = 0 ⇒ x = - 6