Answer:
x = 4 or x = (-3)/2
Explanation:
Solve for x over the real numbers:
2 x^2 - 5 x - 12 = 0
x = (5 ± sqrt((-5)^2 - 4×2 (-12)))/(2×2) = (5 ± sqrt(25 + 96))/4 = (5 ± sqrt(121))/4:
x = (5 + sqrt(121))/4 or x = (5 - sqrt(121))/4
sqrt(121) = sqrt(11^2) = 11:
x = (5 + 11)/4 or x = (5 - 11)/4
(5 + 11)/4 = 16/4 = 4:
x = 4 or x = (5 - 11)/4
(5 - 11)/4 = -6/4 = -3/2:
Answer: x = 4 or x = (-3)/2