Question 82589
A=1/2h(B+b)
I need to solve for b, 
:
Get rid of the fraction, multiply equation by 2, you then have:
h(B + b) = 2A
:
Divide both sides by h, and you have:
B + b = {{{2A/h}}}
:
Subtract B from both sides:
b = {{{2A/h}}} - B