For this case we have the following equation:
[tex]A = \frac {h * (b_ {1} + b_ {2})} {2}[/tex]
We clear [tex]b_ {1}[/tex]:
We multiply by 2 on both sides of the equation:
[tex]2A = h * (b_ {1} + b_ {2})[/tex]
We divide between h on both sides:
[tex]\frac {2A} {h} = b_ {1} + b_ {2}[/tex]
We subtract [tex]b_ {2}[/tex] from both sides of the equation:
[tex]b_ {1} = \frac {2A} {h} -b_ {2}[/tex]
Answer:
[tex]b_ {1} = \frac {2A} {h} -b_ {2}[/tex]
