$\displaystyle P=2l+ 2w$

We have the perimeter and the width, so we can plug those values into our equation and solve for our unknown. 

$\displaystyle 100=2l+2(18)$

$\displaystyle 100=2l+36$

Subtract $\displaystyle 36$ from both sides

$\displaystyle 100-36=2l+36-36$

$\displaystyle 64=2l$

Divide $\displaystyle 2$ by both sides

$\displaystyle \frac{64}{2}=\frac{2l}{2}$

$\displaystyle 32=l$

$\displaystyle P=2l+ 2w$

We have the perimeter and the width, so we can plug those values into our equation and solve for our unknown. 

$\displaystyle 50=2l+2(7)$

$\displaystyle 50=2l+14$

Subtract $\displaystyle 14$ from both sides

$\displaystyle 50-14=2l+14-14$

$\displaystyle 36=2l$

Divide $\displaystyle 2$ by both sides

$\displaystyle \frac{36}{2}=\frac{2l}{2}$

$\displaystyle 18=l$

$\displaystyle P=2l+ 2w$

We have the perimeter and the width, so we can plug those values into our equation and solve for our unknown. 

$\displaystyle 86=2l+2(18)$

$\displaystyle 86=2l+36$

Subtract $\displaystyle 36$ from both sides

$\displaystyle 88-36=2l+36-36$

$\displaystyle 50=2l$

Divide $\displaystyle 2$ by both sides

$\displaystyle \frac{50}{2}=\frac{2l}{2}$

$\displaystyle 25=l$

$\displaystyle P=2l+ 2w$

We have the perimeter and the width, so we can plug those values into our equation and solve for our unknown. 

$\displaystyle 44=2l+2(11)$

$\displaystyle 44=2l+22$

Subtract $\displaystyle 22$ from both sides

$\displaystyle 44-22=2l+22-22$

$\displaystyle 22=2l$

Divide $\displaystyle 2$ by both sides

$\displaystyle \frac{22}{2}=\frac{2l}{2}$

$\displaystyle 11=l$

$\displaystyle P=2l+ 2w$

We have the perimeter and the width, so we can plug those values into our equation and solve for our unknown. 

$\displaystyle 60=2l+2(10)$

$\displaystyle 60=2l+20$

Subtract $\displaystyle 20$ from both sides

$\displaystyle 60-20=2l+20-20$

$\displaystyle 40=2l$

Divide $\displaystyle 2$ by both sides

$\displaystyle \frac{40}{2}=\frac{2l}{2}$

$\displaystyle 20=l$

$\displaystyle P=2l+ 2w$

We have the perimeter and the width, so we can plug those values into our equation and solve for our unknown. 

$\displaystyle 94=2l+2(33)$

$\displaystyle 94=2l+66$

Subtract $\displaystyle 66$ from both sides

$\displaystyle 94-66=2l+66-66$

$\displaystyle 28=2l$

Divide $\displaystyle 2$ by both sides

$\displaystyle \frac{28}{2}=\frac{2l}{2}$

$\displaystyle 14=l$

$\displaystyle P=2l+ 2w$

We have the perimeter and the width, so we can plug those values into our equation and solve for our unknown. 

$\displaystyle 58=2l+2(16)$

$\displaystyle 58=2l+32$

Subtract $\displaystyle 32$ from both sides

$\displaystyle 58-32=2l+32-32$

$\displaystyle 26=2l$

Divide $\displaystyle 2$ by both sides

$\displaystyle \frac{26}{2}=\frac{2l}{2}$

$\displaystyle 13=l$

We have the perimeter and the width, so we can plug those values into our equation and solve for our unknown. 

$\displaystyle 62=2l+2(12)$

$\displaystyle 62=2l+24$

Subtract $\displaystyle 24$ from both sides

$\displaystyle 62-24=2l+24-24$

$\displaystyle 38=2l$

Divide $\displaystyle 2$ by both sides

$\displaystyle \frac{38}{2}=\frac{2l}{2}$

$\displaystyle 19=l$

$\displaystyle P=2l+ 2w$

We have the perimeter and the width, so we can plug those values into our equation and solve for our unknown. 

$\displaystyle 70=2l+2(16)$

$\displaystyle 70=2l+32$

Subtract $\displaystyle 32$ from both sides

$\displaystyle 70-32=2l+32-32$

$\displaystyle 38=2l$

Divide $\displaystyle 2$ by both sides

$\displaystyle \frac{38}{2}=\frac{2l}{2}$

$\displaystyle 19=l$

$\displaystyle P=2l+ 2w$

We have the perimeter and the width, so we can plug those values into our equation and solve for our unknown. 

$\displaystyle 40=2l+2(8)$

$\displaystyle 40=2l+16$

Subtract $\displaystyle 16$ from both sides

$\displaystyle 40-16=2l+16-16$

$\displaystyle 24=2l$

Divide $\displaystyle 2$ by both sides

$\displaystyle \frac{24}{2}=\frac{2l}{2}$

$\displaystyle 12=l$