a = 1/2bh, solve for b
that means -----> isolate the variable b
so
[tex]\begin{gathered} a=\frac{1}{2}\cdot b\cdot h \\ \text{Multiply by 2 both sides} \\ 2a=b\cdot h \\ \text{Divide by h both sides} \\ b=\frac{2a}{h} \end{gathered}[/tex]therefore
the answer is
