Question

Solve quadratic equation by factoring:
36x^3 + X^2 -21x = 0

Answer 1

take x as the factor
x(36x^2+x-21)=0
=> 36x^2 +x -21 = 0
x= + 0.7637 or x = -0.7637 Used calculator to solve

Answer 2

Yeah, I need to show work in between..

Answer 3

I feel like this cannot be factored to solve the equation.

Answer 4

With some work u can complete the square....

Answer 5

U go (x+1/2)^2 multiplied by 36 etc and your roots happily come out to rationals.

See here:

http://www.wolframalpha.com/input/?i=36x^2+%2Bx+-21