Question

Solve for the indicated variable.
A=h/2 (a+b); for h

Answer 1

A=h/2(a+b)

Multiply both sides by 2(a+b)

We get 2(a+b)A= h

Now multiply out 2(a+b)A

We get 2Aa +2Ab =h

Divide both sides by A

We get 2Aa+ 2Ab = h

Now take 2Ab to the right side

2Aa = h -2Ab
a= (h -2Ab)/2A

Answer 2

that's incorrect @xxccjxx

Answer 3

Do you mean how do you solve for the variable a?

That would just indicate we need to isolate a.

So first, multiply both sides by 2/h to move it to the left.
2A / h = a+b
subtract b
a=(2A / h) - b