The perimeter of a rectangular garden is 690 ft. The width is 30 less than twice the length. Find the dimensions of the garden.
690/2 is the length of the width+length, which is 345. if w=2l-30 and w+l=345, then subtracting one equation from the other, we have
l=-2l+375
3l=375
length=$\boxed{125}$ft
now that we have the length, we can plug it in with one of the equations to solve for w:
w+125=345
width=$\boxed{220}$ft