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