a+1=3(2d+1)

Solution for a+1=3(2d+1) equation:

Simplifying
a + 1 = 3(2d + 1)

Reorder the terms:
1 + a = 3(2d + 1)

Reorder the terms:
1 + a = 3(1 + 2d)
1 + a = (1 * 3 + 2d * 3)
1 + a = (3 + 6d)

Solving
1 + a = 3 + 6d

Solving for variable 'a'.

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

Add '-1' to each side of the equation.
1 + -1 + a = 3 + -1 + 6d

Combine like terms: 1 + -1 = 0
0 + a = 3 + -1 + 6d
a = 3 + -1 + 6d

Combine like terms: 3 + -1 = 2
a = 2 + 6d

Simplifying
a = 2 + 6d