r(r+3)=10

Solution for r(r+3)=10 equation:

Simplifying
r(r + 3) = 10

Reorder the terms:
r(3 + r) = 10
(3 * r + r * r) = 10
(3r + r2) = 10

Solving
3r + r2 = 10

Solving for variable 'r'.

Reorder the terms:
-10 + 3r + r2 = 10 + -10

Combine like terms: 10 + -10 = 0
-10 + 3r + r2 = 0

Factor a trinomial.
(-5 + -1r)(2 + -1r) = 0

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

Simplifying
2 + -1r = 0

Solving
2 + -1r = 0

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

Add '-2' to each side of the equation.
2 + -2 + -1r = 0 + -2

Combine like terms: 2 + -2 = 0
0 + -1r = 0 + -2
-1r = 0 + -2

Combine like terms: 0 + -2 = -2
-1r = -2

Divide each side by '-1'.
r = 2

Simplifying
r = 2
Solution
r = {-5, 2}