Hey there! I'm happy to help!
The perimeter is the distance around a shape. Let's add up the lengths of our sides to ind it.
x+5x-2+7x-3
We combine all of the x values.
x+5x+7x=13x
And all of the constants.
-2-3=-5
Therefore, the perimeter is 13x-5.
Have a wonderful day! :D