-78=-6(1-5r)+7

Solution for -78=-6(1-5r)+7 equation:

Simplifying
-78 = -6(1 + -5r) + 7
-78 = (1 * -6 + -5r * -6) + 7
-78 = (-6 + 30r) + 7

Reorder the terms:
-78 = -6 + 7 + 30r

Combine like terms: -6 + 7 = 1
-78 = 1 + 30r

Solving
-78 = 1 + 30r

Solving for variable 'r'.

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

Add '-30r' to each side of the equation.
-78 + -30r = 1 + 30r + -30r

Combine like terms: 30r + -30r = 0
-78 + -30r = 1 + 0
-78 + -30r = 1

Add '78' to each side of the equation.
-78 + 78 + -30r = 1 + 78

Combine like terms: -78 + 78 = 0
0 + -30r = 1 + 78
-30r = 1 + 78

Combine like terms: 1 + 78 = 79
-30r = 79

Divide each side by '-30'.
r = -2.633333333

Simplifying
r = -2.633333333