To solve for a, we need to isolate a on one side of the equation.

Starting with the equation:

B/a + 3 = 7/6

Subtracting 3 from both sides:

B/a = 7/6 - 3

Combining the fractions on the right side:

B/a = 7/6 - 18/6
B/a = -11/6

To solve for a, we can multiply both sides by a:

a (B/a) = a (-11/6)

This simplifies to:

B = -11a/6

Finally, we can multiply both sides by 6 to eliminate the fraction:

6B = -11a

Dividing by -11 on both sides:

a = -6B/11

Therefore, the solution for a is a = -6B/11.