Answer:
(2A /h) - b1 = b2
Step-by-step explanation:
A = 1/2 h ( b1 + b2)
Multiply each side by 2
2A = 2*1/2 h ( b1 + b2)
2A = h ( b1 + b2)
Divide each side by h
2A/h= h/h ( b1 + b2)
2A/h= b1 + b2
Subtract b1 from each side
2A /h - b1 = b2
