Given:
W(width) = (6L) - 9
L(length) = L
Equation:
2( [ 6L ] - 9) + 2 (L) = 150
= 12L - 18 + 2L = 150
= 12L + 2L = 150 + 18
=14L = 168
L = 168/14, so the length is 12. Let's check our work.
Width: 6(12) - 9 = 72 - 9 = 63
Length: 12
Since there are two lines of width and two lines of length:
2(12) + 2(63) = 24 + 126, which gives you a perimeter of 150 mm.
Hope this helped.
