-4(r+8)+9(r+8)=71

Solution for -4(r+8)+9(r+8)=71 equation:

Simplifying
-4(r + 8) + 9(r + 8) = 71

Reorder the terms:
-4(8 + r) + 9(r + 8) = 71
(8 * -4 + r * -4) + 9(r + 8) = 71
(-32 + -4r) + 9(r + 8) = 71

Reorder the terms:
-32 + -4r + 9(8 + r) = 71
-32 + -4r + (8 * 9 + r * 9) = 71
-32 + -4r + (72 + 9r) = 71

Reorder the terms:
-32 + 72 + -4r + 9r = 71

Combine like terms: -32 + 72 = 40
40 + -4r + 9r = 71

Combine like terms: -4r + 9r = 5r
40 + 5r = 71

Solving
40 + 5r = 71

Solving for variable 'r'.

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

Add '-40' to each side of the equation.
40 + -40 + 5r = 71 + -40

Combine like terms: 40 + -40 = 0
0 + 5r = 71 + -40
5r = 71 + -40

Combine like terms: 71 + -40 = 31
5r = 31

Divide each side by '5'.
r = 6.2

Simplifying
r = 6.2