Any fraction where top and bottom of 30 over 100 are multiplied/divided by the same number

3/10
6/20
9/30
12/40
15/50
18/60
21/70
24/80
27/90
...
60/200

A = l * w    (definition)
l = w + 8    (define length)

A = (w + 8) * w   (substitute l with w+8)
105 = (w + 8) * w  (substitute A with 105)
105 = w * w + 8w  (multiply both terms w+8 with w)

w * 2 + 8 * w - 105 = … Read more