Please help I don't know how to do this

Question

The length of a new rectangular playing field is 6 yards longer than triple the width. If the perimeter of the rectangular playing field is 476 ​yards, what are its​ dimensions?

Answer 1

L = 6+3w

2L+2w = 476

L+w = 238

6+3w +w = 238

4w = 232

w = 58 yards

L = 6+3(58) = 6+168 = 174 yards

2(174)+2(58) = 348+116 = 464 = Perimeter

dimensions are 58 by 174 yards