SOLUTION: One solution of {{{ kx^2+3x-k=0 }}} is -2. Find the other solution using quadratic formula (or using other ways)

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: One solution of {{{ kx^2+3x-k=0 }}} is -2. Find the other solution using quadratic formula (or using other ways)      Log On


   

Question 982938: One solution of +kx%5E2%2B3x-k=0+ is -2. Find the other solution using quadratic formula (or using other ways)
Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
for x = -2, we have
k*(-2)^2 + 3*(-2) - k = 0
4k -6 - k = 0
3k = 6
k = 2, therefore
2x^2 +3x -2 = 0
x = (-3 + square root(9 - 4*(2)*(-2))) / 4 = 0.5
x = (-3 - square root(9 - 4*(2)*(-2))) / 4 = -2
therefore,
the solutions for x are x = -2, x = 0.5