Question

I need help! I don't understand this!

Answer 1

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)

$A=\frac{1}{2}bh$   Multiply 2 on both sides to get rid of the 1/2

2A = bh        Divide h on both sides

$\frac{2A}{h} =b$

6.) Solve for r

$C=2\pi r$      Divide 2 and $\pi$ on both sides

$\frac{C}{2\pi } =r$