90x^2-71x-9=0

Solution for 90x^2-71x-9=0 equation:

Simplifying
90x2 + -71x + -9 = 0

Reorder the terms:
-9 + -71x + 90x2 = 0

Solving
-9 + -71x + 90x2 = 0

Solving for variable 'x'.

Factor a trinomial.
(-1 + -9x)(9 + -10x) = 0

Subproblem 1
Set the factor '(-1 + -9x)' equal to zero and attempt to solve:

Simplifying
-1 + -9x = 0

Solving
-1 + -9x = 0

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

Add '1' to each side of the equation.
-1 + 1 + -9x = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -9x = 0 + 1
-9x = 0 + 1

Combine like terms: 0 + 1 = 1
-9x = 1

Divide each side by '-9'.
x = -0.1111111111

Simplifying
x = -0.1111111111
Subproblem 2
Set the factor '(9 + -10x)' equal to zero and attempt to solve:

Simplifying
9 + -10x = 0

Solving
9 + -10x = 0

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

Add '-9' to each side of the equation.
9 + -9 + -10x = 0 + -9

Combine like terms: 9 + -9 = 0
0 + -10x = 0 + -9
-10x = 0 + -9

Combine like terms: 0 + -9 = -9
-10x = -9

Divide each side by '-10'.
x = 0.9

Simplifying
x = 0.9
Solution
x = {-0.1111111111, 0.9}