Answer:
length is 10, width is 7
Step-by-step explanation:
Area of a rectangle = length * width = lw
Area is known to be 70
length = twice width - 4 = 2w-4 = l
width=w
so A = lw = (2w-4)w = 70
(2w-4)w=70
2w^2-4w=70
2w^2-4w-70=0, divide by 2
w^2 - 2w - 35 = 0, not sure how your class solves these, I see visually
(w-7)(w+5)=0
w=7 or w=-5, -5 makes no sense in the real world (negative length), so w=7
l = 2w-4 = 2(7)-4 = 14-4 = 10
