Using Balance

Use balance to solve for the variables in the following equations:

1. If $x+2=12$, what is $x$? $\mathbf{10}$
2. If $x=5$, what is $2x$?  $\mathbf{10}$
3. If $x+21=80$, what is $2(x+21)$?  $\mathbf{160}$
4. If $x=25$ what is $\sqrt{x}$?  $\mathbf{5}$
5. If $\dfrac{x}{5}=3$, what is $x$?  $\mathbf{15}$
6. If ${x}=-9$, what is $\dfrac{x}{3}$?  $\mathbf{-3}$
7. If ${x}=\dfrac{1}{2}$, what is $2x$?  $\mathbf{1}$
8. If ${x}=-4$, what is $x^2$?  $\mathbf{16}$
9. If ${x}=8$, what is $x^3$?  $\mathbf{512}$
10. If $ab=12$, what is $3ab$?  $\mathbf{36}$