-9r^2+100r-100=0

Solution for -9r^2+100r-100=0 equation:

Simplifying
-9r2 + 100r + -100 = 0

Reorder the terms:
-100 + 100r + -9r2 = 0

Solving
-100 + 100r + -9r2 = 0

Solving for variable 'r'.

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

Subproblem 1
Set the factor '(-10 + r)' equal to zero and attempt to solve:

Simplifying
-10 + r = 0

Solving
-10 + r = 0

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

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

Combine like terms: -10 + 10 = 0
0 + r = 0 + 10
r = 0 + 10

Combine like terms: 0 + 10 = 10
r = 10

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

Simplifying
10 + -9r = 0

Solving
10 + -9r = 0

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

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

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

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

Divide each side by '-9'.
r = 1.111111111

Simplifying
r = 1.111111111
Solution
r = {10, 1.111111111}