The length of a store is 21 2/3 feet, and the area is 325 square feet, what is the width of the store?

325 divided by area 21 2/3. always area divided by length

Equation for length:
L=3w-35

By inputting this into the equation to find the perimeter we get:
2(3w-35)+2w=190
Distribute
6w-70+2w=190
Add like terms
8w=260
Divide both sides by 8
w=32.5
The width is 32.5cm

To find the length input w into the equation for length
L=3(32.5)-35
L=97.5-35
L=62.5
The length is 62.5cm

Check that the solution is correct by inputting the solutions to the perimeter equation

2L+2w=190
2(62.5)+2(32.5)=190
125+65=190
190=190

I hope this helps :)