SOLUTION: The area of the rubber counting for a flat roof was 96ft. the rectangular frame the carpenter built for the flat roof has dimensions such s the length is 4 feet longer than width w

Question 997861: The area of the rubber counting for a flat roof was 96ft. the rectangular frame the carpenter built for the flat roof has dimensions such s the length is 4 feet longer than width what are the dimensions of the frame
Answer by addingup(3677) (Show Source): You can put this solution on YOUR website!
Area of the rectangle:
L x W = 96 And the problem says that:
W= L-4 Let's use this value for W in the formula above:
(L-4)*L= 96 Multiply on left:
L^2-4L= 96 Subtract 96 on both sides
L^2-4L-96= 0 Factor the left (FOIL)
(L+8)(L-12)= 0 Break this into 2 equations:
L+8= 0 or L-12= 0
L= -8 or L= 12 We know we are looking for a positive number, so discard the -8 and let's try the 12:
12*(12-4)=
12*8= 96 We've got the correct answer
RELATED QUESTIONS
The area of the rubber coating for a flat roof was 96 ft^2. The rectangular frame the... (answered by Alan3354,josgarithmetic)

A carpenter is putting a skylight on a roof. If the roof measures 10x +89 by 7x+7 and the (answered by josmiceli)

A rubber ice-hockey puck has a 3.2 in. diameter. What is the surface area of one flat... (answered by Alan3354)

19 Roofing: A flat roof 28 ft long and 16 ft wide has a 3-in depth of water sitting on... (answered by bucky)

Roofing: A flat roof 28 ft long and 16 ft wide has a 3 in depth of water sittin on it.... (answered by checkley71)

A flat roof 25' x 46' has water 2 inches deep on it. How many cubic feet of water does it (answered by Alan3354)

I am installing a one-sided pitched roof that faces south on a 4X4 meter room on the flat (answered by Theo)

The area of a rectangular roof on a doghouse is 765 square inches, the length of the roof (answered by Cromlix)

The roof of the building shown below has a span of 48 feet. the rafters upon which the... (answered by Alan3354)