Answer:
length is 7cm, and the width is 4cm
Explanation:
The length of a picture frame is 1cm less than twice the width(frame is NOT a square). The area is 28cm^2. Find the length and width of the picture frame.
The area of the frame = Length * Width
A = LW
If the length of a picture frame is 1cm less than twice the width, then;
L = 2W - 1
Substitute into the formula;
A = (2W-1)W
A = 2W^2 - W
28 = 2W^2 - W
2W^2 - W - 28 = 0
2W^2 - 8W +7W- 28 = 0
2W(W-4)+7(W-4) = 0
2W+7 = 0 and W - 4 = 0
W =- -7/2 and W = 4
Width cannot be negative
W = 4cm
Since A = LW
L = A/W
L = 28/4
L = 7cm
Hence the length is 7cm, and the width is 4cm