87=3(7n+1)

Solution for 87=3(7n+1) equation:

Simplifying
87 = 3(7n + 1)

Reorder the terms:
87 = 3(1 + 7n)
87 = (1 * 3 + 7n * 3)
87 = (3 + 21n)

Solving
87 = 3 + 21n

Solving for variable 'n'.

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

Add '-21n' to each side of the equation.
87 + -21n = 3 + 21n + -21n

Combine like terms: 21n + -21n = 0
87 + -21n = 3 + 0
87 + -21n = 3

Add '-87' to each side of the equation.
87 + -87 + -21n = 3 + -87

Combine like terms: 87 + -87 = 0
0 + -21n = 3 + -87
-21n = 3 + -87

Combine like terms: 3 + -87 = -84
-21n = -84

Divide each side by '-21'.
n = 4

Simplifying
n = 4