[tex]b_{2}[/tex] = [tex]\frac{2A}{h}[/tex] - [tex]b_{1}[/tex]
multiply both sides by 2 to eliminate the fraction
([tex]b_{1}[/tex] + [tex]b_{2}[/tex] )h = 2A
divide both sides by h
[tex]b_{1}[/tex] + [tex]b_{2}[/tex] = [tex]\frac{2A}{h}[/tex]
subtract [tex]b_{1}[/tex] from both sides
[tex]b_{2}[/tex] = [tex]\frac{2A}{h}[/tex] - [tex]b_{1}[/tex]
