Answer :

Answer:  

b=2A/h-a

Step-by-step explanation:  

A=1/2h(a+b)

Multiplying by 2

2A=h(a+b)

Dividing by h  

2A/h=a+b

Subtracting a  

2A/h-a =b

b=2A/h-a

Answer:

2 ⋅ A /h -   a = b

Explanation:

Multiplying by  2 :

2 A  =  h  ( a + b )

dividing by  h

2 A /h =  a  +  b

substracting  a

2  ⋅  A /h  −  a  = b