Question

using the quadratic formula, find the solutions to 3x^2 + 18x + 24 = 0
x = -2
x = -2, x = -4
x =4
x = 4, x = 2

Answer 1

Use the quadratic formula x = [-b ± sqrt(b^2 − 4ac)]/(2a) with a = 3, b = 18, c = 24.

Discriminant: 18^2 − 4·3·24 = 324 − 288 = 36, sqrt = 6.

x = [−18 ± 6]/(2·3) = [−18 ± 6]/6 gives x = (−12)/6 = −2 and x = (−24)/6 = −4.

So the solutions are x = −2 and x = −4.