The width of a rectangle is 2 inches more than three times the length. if the perimeter is 124 inches, what are the dimensions of the rectangle? (find both length and width)

Let x=L.
Then let 3x+2=W
Giving you 124=(x)+(x)+(3x+2)+(3x+2)
Then simplify and solve.
124=8x+4
124-4=8x
120=8x
120/8=x
15=x

Then put that value back into the original equations to find the dimensions.
x=L
15=Length
and
3x+2=W
3(15)+2=W
77=Width