7r^2+39r-18=0

Solution for 7r^2+39r-18=0 equation:

Simplifying
7r2 + 39r + -18 = 0

Reorder the terms:
-18 + 39r + 7r2 = 0

Solving
-18 + 39r + 7r2 = 0

Solving for variable 'r'.

Factor a trinomial.
(-6 + -1r)(3 + -7r) = 0

Subproblem 1
Set the factor '(-6 + -1r)' equal to zero and attempt to solve:

Simplifying
-6 + -1r = 0

Solving
-6 + -1r = 0

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

Add '6' to each side of the equation.
-6 + 6 + -1r = 0 + 6

Combine like terms: -6 + 6 = 0
0 + -1r = 0 + 6
-1r = 0 + 6

Combine like terms: 0 + 6 = 6
-1r = 6

Divide each side by '-1'.
r = -6

Simplifying
r = -6
Subproblem 2
Set the factor '(3 + -7r)' equal to zero and attempt to solve:

Simplifying
3 + -7r = 0

Solving
3 + -7r = 0

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

Add '-3' to each side of the equation.
3 + -3 + -7r = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -7r = 0 + -3
-7r = 0 + -3

Combine like terms: 0 + -3 = -3
-7r = -3

Divide each side by '-7'.
r = 0.4285714286

Simplifying
r = 0.4285714286
Solution
r = {-6, 0.4285714286}