Solution
Switch sides so that the right side is the left side
1/2h (B + b) = A
Now multiply both sides by 2
2 • 1/2h (B + b) = A • 2
Simplify the equation
h (B + b) = 2A
Now divide both sides by h
(h (B + b))/h = 2A/h
Simplify the equation
B + b = 2A/h
Subtract B from both sides
B + b - B = 2A/h - B
Simplify the equation
b = 2A/h - B
Therefore b = 2A/h - B
