r^2+20r-4800=0

Solution for r^2+20r-4800=0 equation:

Simplifying
r2 + 20r + -4800 = 0

Reorder the terms:
-4800 + 20r + r2 = 0

Solving
-4800 + 20r + r2 = 0

Solving for variable 'r'.

Factor a trinomial.
(-80 + -1r)(60 + -1r) = 0

Subproblem 1
Set the factor '(-80 + -1r)' equal to zero and attempt to solve:

Simplifying
-80 + -1r = 0

Solving
-80 + -1r = 0

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

Add '80' to each side of the equation.
-80 + 80 + -1r = 0 + 80

Combine like terms: -80 + 80 = 0
0 + -1r = 0 + 80
-1r = 0 + 80

Combine like terms: 0 + 80 = 80
-1r = 80

Divide each side by '-1'.
r = -80

Simplifying
r = -80
Subproblem 2
Set the factor '(60 + -1r)' equal to zero and attempt to solve:

Simplifying
60 + -1r = 0

Solving
60 + -1r = 0

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

Add '-60' to each side of the equation.
60 + -60 + -1r = 0 + -60

Combine like terms: 60 + -60 = 0
0 + -1r = 0 + -60
-1r = 0 + -60

Combine like terms: 0 + -60 = -60
-1r = -60

Divide each side by '-1'.
r = 60

Simplifying
r = 60
Solution
r = {-80, 60}