SOLUTION: Solve the equation 3x^2 + 2x = √(3x^2 + 2x) without squaring both sides.

Algebra ->  Radicals -> SOLUTION: Solve the equation 3x^2 + 2x = √(3x^2 + 2x) without squaring both sides.      Log On


   

Question 930796: Solve the equation 3x^2 + 2x = √(3x^2 + 2x) without squaring both sides.
Answer by josgarithmetic(39621) About Me  (Show Source):
You can put this solution on YOUR website!
Simple Substitution: Let u=3x%5E2%2B2x. This gives u%5E2=u,
u%5E2-u=0
u%28u-1%29=0
u=0 OR u-1=0;


Back-substituting this means highlight_green%283x%5E2%2B2x=0%29 OR highlight_green%283x%5E2%2B2x-1=0%29
and no further need to square both sides. Each of these can be solved for x.