posted by Jill .
Write a quadratic equation with real coefficients if one of the solutions is -5 + 7i
complex roots always come in pairs, so the other root is -5 - 7i
sum of roots = (-5+7i) + (-5-7i) = -10
product of roots = (-5+7i)(-5-7i)
= 25 - 49i^2 = 25+49 = 74
x^2 + 10x + 74 = 0