150=3(7r+1)

Solution for 150=3(7r+1) equation:

Simplifying
150 = 3(7r + 1)

Reorder the terms:
150 = 3(1 + 7r)
150 = (1 * 3 + 7r * 3)
150 = (3 + 21r)

Solving
150 = 3 + 21r

Solving for variable 'r'.

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

Add '-21r' to each side of the equation.
150 + -21r = 3 + 21r + -21r

Combine like terms: 21r + -21r = 0
150 + -21r = 3 + 0
150 + -21r = 3

Add '-150' to each side of the equation.
150 + -150 + -21r = 3 + -150

Combine like terms: 150 + -150 = 0
0 + -21r = 3 + -150
-21r = 3 + -150

Combine like terms: 3 + -150 = -147
-21r = -147

Divide each side by '-21'.
r = 7

Simplifying
r = 7