r(r+2)=440

Solution for r(r+2)=440 equation:

Simplifying
r(r + 2) = 440

Reorder the terms:
r(2 + r) = 440
(2 * r + r * r) = 440
(2r + r2) = 440

Solving
2r + r2 = 440

Solving for variable 'r'.

Reorder the terms:
-440 + 2r + r2 = 440 + -440

Combine like terms: 440 + -440 = 0
-440 + 2r + r2 = 0

Factor a trinomial.
(-22 + -1r)(20 + -1r) = 0

Subproblem 1
Set the factor '(-22 + -1r)' equal to zero and attempt to solve:

Simplifying
-22 + -1r = 0

Solving
-22 + -1r = 0

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

Add '22' to each side of the equation.
-22 + 22 + -1r = 0 + 22

Combine like terms: -22 + 22 = 0
0 + -1r = 0 + 22
-1r = 0 + 22

Combine like terms: 0 + 22 = 22
-1r = 22

Divide each side by '-1'.
r = -22

Simplifying
r = -22
Subproblem 2
Set the factor '(20 + -1r)' equal to zero and attempt to solve:

Simplifying
20 + -1r = 0

Solving
20 + -1r = 0

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

Add '-20' to each side of the equation.
20 + -20 + -1r = 0 + -20

Combine like terms: 20 + -20 = 0
0 + -1r = 0 + -20
-1r = 0 + -20

Combine like terms: 0 + -20 = -20
-1r = -20

Divide each side by '-1'.
r = 20

Simplifying
r = 20
Solution
r = {-22, 20}