a rectangle has a perimetr of 30m, if the length is at least twice the width,find the range of possible values of the width of the rectangle.
l>=2w
2L+2w=30
2l=30-2w
l=15-w
15-w>=2w
w<=3 check that
2L+2w=30
2l=30-2w
l=15-w
15-w>=2w
w<=3 check that