7 x 3 = 21 so it is 21 ft cm your welcome
-5+d/3=5
d/3-5=5
d-3.5/3=5
d-15/3=5
d-15=15
(d-15)+15=15+15
d-15+15=30
d=30
Hope this helps kiddo
Remember that the area of a rectangle is the length of the rectangle multiplied by the width of the rectangle.
In this case, we could say (where is the area of the rectangle):
Substituting the values the problem gave us for and , we can find the formula for in terms of , which is:
The formula for the area of the rectangle would be A(x) = 10x³ - 20x² + 65x.