Simplifying 
-20x2 = 36x 
 
Solving 
-20x2 = 36x 
 
Solving for variable 'x'. 
 
Reorder the terms: 
-36x + -20x2 = 36x + -36x 
 
Combine like terms: 36x + -36x = 0 
-36x + -20x2 = 0 
 
Factor out the Greatest Common Factor (GCF), '-4x'. 
-4x(9 + 5x) = 0 
 
Ignore the factor -4. ._.