r^2-18*r+56=0

Solution for r^2-18*r+56=0 equation:

Simplifying
r2 + -18r + 56 = 0

Reorder the terms:
56 + -18r + r2 = 0

Solving
56 + -18r + r2 = 0

Solving for variable 'r'.

Factor a trinomial.
(4 + -1r)(14 + -1r) = 0

Subproblem 1
Set the factor '(4 + -1r)' equal to zero and attempt to solve:

Simplifying
4 + -1r = 0

Solving
4 + -1r = 0

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

Add '-4' to each side of the equation.
4 + -4 + -1r = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -1r = 0 + -4
-1r = 0 + -4

Combine like terms: 0 + -4 = -4
-1r = -4

Divide each side by '-1'.
r = 4

Simplifying
r = 4
Subproblem 2
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
Solution
r = {4, 14}