78=3(5r+1)

Solution for 78=3(5r+1) equation:

Simplifying
78 = 3(5r + 1)

Reorder the terms:
78 = 3(1 + 5r)
78 = (1 * 3 + 5r * 3)
78 = (3 + 15r)

Solving
78 = 3 + 15r

Solving for variable 'r'.

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

Add '-15r' to each side of the equation.
78 + -15r = 3 + 15r + -15r

Combine like terms: 15r + -15r = 0
78 + -15r = 3 + 0
78 + -15r = 3

Add '-78' to each side of the equation.
78 + -78 + -15r = 3 + -78

Combine like terms: 78 + -78 = 0
0 + -15r = 3 + -78
-15r = 3 + -78

Combine like terms: 3 + -78 = -75
-15r = -75

Divide each side by '-15'.
r = 5

Simplifying
r = 5