r(r+9)=70

Solution for r(r+9)=70 equation:

Simplifying
r(r + 9) = 70

Reorder the terms:
r(9 + r) = 70
(9 * r + r * r) = 70
(9r + r2) = 70

Solving
9r + r2 = 70

Solving for variable 'r'.

Reorder the terms:
-70 + 9r + r2 = 70 + -70

Combine like terms: 70 + -70 = 0
-70 + 9r + r2 = 0

Factor a trinomial.
(-14 + -1r)(5 + -1r) = 0

Subproblem 1
Set the factor '(-14 + -1r)' equal to zero and attempt to solve:

Simplifying
-14 + -1r = 0

Solving
-14 + -1r = 0

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

Add '14' to each side of the equation.
-14 + 14 + -1r = 0 + 14

Combine like terms: -14 + 14 = 0
0 + -1r = 0 + 14
-1r = 0 + 14

Combine like terms: 0 + 14 = 14
-1r = 14

Divide each side by '-1'.
r = -14

Simplifying
r = -14
Subproblem 2
Set the factor '(5 + -1r)' equal to zero and attempt to solve:

Simplifying
5 + -1r = 0

Solving
5 + -1r = 0

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

Add '-5' to each side of the equation.
5 + -5 + -1r = 0 + -5

Combine like terms: 5 + -5 = 0
0 + -1r = 0 + -5
-1r = 0 + -5

Combine like terms: 0 + -5 = -5
-1r = -5

Divide each side by '-1'.
r = 5

Simplifying
r = 5
Solution
r = {-14, 5}