When they say to solve for a variable, they want you to isolate/get the variable by itself.
5.) Solve for b (get b by itself)
[tex]A=\frac{1}{2}bh[/tex] Multiply 2 on both sides to get rid of the 1/2
2A = bh Divide h on both sides
[tex]\frac{2A}{h} =b[/tex]
6.) Solve for r
[tex]C=2\pi r[/tex] Divide 2 and [tex]\pi[/tex] on both sides
[tex]\frac{C}{2\pi } =r[/tex]
