75x-36=-21x^2

Solution for 75x-36=-21x^2 equation:

Simplifying
75x + -36 = -21x2

Reorder the terms:
-36 + 75x = -21x2

Solving
-36 + 75x = -21x2

Solving for variable 'x'.

Combine like terms: -21x2 + 21x2 = 0
-36 + 75x + 21x2 = 0

Factor out the Greatest Common Factor (GCF), '3'.
3(-12 + 25x + 7x2) = 0

Factor a trinomial.
3((-4 + -1x)(3 + -7x)) = 0

Ignore the factor 3.
Subproblem 1
Set the factor '(-4 + -1x)' equal to zero and attempt to solve:

Simplifying
-4 + -1x = 0

Solving
-4 + -1x = 0

Move all terms containing x to the left, all other terms to the right.

Add '4' to each side of the equation.
-4 + 4 + -1x = 0 + 4

Combine like terms: -4 + 4 = 0
0 + -1x = 0 + 4
-1x = 0 + 4

Combine like terms: 0 + 4 = 4
-1x = 4

Divide each side by '-1'.
x = -4

Simplifying
x = -4
Subproblem 2
Set the factor '(3 + -7x)' equal to zero and attempt to solve:

Simplifying
3 + -7x = 0

Solving
3 + -7x = 0

Move all terms containing x to the left, all other terms to the right.

Add '-3' to each side of the equation.
3 + -3 + -7x = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -7x = 0 + -3
-7x = 0 + -3

Combine like terms: 0 + -3 = -3
-7x = -3

Divide each side by '-7'.
x = 0.4285714286

Simplifying
x = 0.4285714286
Solution
x = {-4, 0.4285714286}