Respuesta :

times both sides by 3/1
3A=(a+b)h
distribute
3A=ah+bh
minus ah from both sides
3A-ah=bh
divide both sides by h
[tex]\frac{3A-ah}{h}=b[/tex]
[tex]b=\frac{3A-ah}{h}[/tex]
or
[tex]b=\frac{3A}{h}-a[/tex]