-3(3r+6)+4(r+5)=-28

Solution for -3(3r+6)+4(r+5)=-28 equation:

Simplifying
-3(3r + 6) + 4(r + 5) = -28

Reorder the terms:
-3(6 + 3r) + 4(r + 5) = -28
(6 * -3 + 3r * -3) + 4(r + 5) = -28
(-18 + -9r) + 4(r + 5) = -28

Reorder the terms:
-18 + -9r + 4(5 + r) = -28
-18 + -9r + (5 * 4 + r * 4) = -28
-18 + -9r + (20 + 4r) = -28

Reorder the terms:
-18 + 20 + -9r + 4r = -28

Combine like terms: -18 + 20 = 2
2 + -9r + 4r = -28

Combine like terms: -9r + 4r = -5r
2 + -5r = -28

Solving
2 + -5r = -28

Solving for variable 'r'.

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

Add '-2' to each side of the equation.
2 + -2 + -5r = -28 + -2

Combine like terms: 2 + -2 = 0
0 + -5r = -28 + -2
-5r = -28 + -2

Combine like terms: -28 + -2 = -30
-5r = -30

Divide each side by '-5'.
r = 6

Simplifying
r = 6