Solve using the quadratic formula 1

Step-by-step explanation:

Unless we set x^2 + 8x + 15 equal to zero, we don't have an equation to be solved.  I will assume that the problem is actually x^2 + 8x + 15 = 0.

The coefficients of this quadratic are {1, 8, 15}, and so the "discriminant" b^2 - 4ac is (8)^2 - 4(1)(15), or 4.  Because the discriminant is positive, we know that there are two real, unequal roots.

Continuing with the quadratic formula and knowing that the discriminant is 4, we get:

      -8 ± √4           -8 ± 2

x = = , or x = -2 ± 1:  x = -3 and x = -5

          2                       2

x=4

step-by-step explanation: