The length of a rectangular piece of steel in a bridge is 4 meters less that double the width. The perimeter of the piece of steel is 40 meters. Find the length of the piece of steel. Find the width of the piece of steel.
I wrote the full problems below. I would like if the full steps could be shown so I will know how to work it out in the future.
*No smart comments needed*
I wrote the full problems below. I would like if the full steps could be shown so I will know how to work it out in the future.
*No smart comments needed*
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Use L and W for the length and width:
L = 2W - 4 [length of a rectangular piece of steel in a bridge is 4 meters less that double the width]
2L + 2W = 40 [perimeter of the piece of steel is 40 meters]
Substitute 2W - 4 (from equation 1) for L in equation 2:
2(2W - 4) + 2W = 40
Multiply out the parentheses:
4W - 8 + 2W = 40
Combine the W terms:
6W - 8 = 40
Add 8 to both sides:
6W = 48
Divide both sides by 6:
W = 8
The steel is 8 meters wide. The length is twice that minus 4 meters or 12 meters.
Check:
2(12) + 2(8) ?= 40
24 + 16 ?= 40
40 = 40 (answers are correct)
L = 2W - 4 [length of a rectangular piece of steel in a bridge is 4 meters less that double the width]
2L + 2W = 40 [perimeter of the piece of steel is 40 meters]
Substitute 2W - 4 (from equation 1) for L in equation 2:
2(2W - 4) + 2W = 40
Multiply out the parentheses:
4W - 8 + 2W = 40
Combine the W terms:
6W - 8 = 40
Add 8 to both sides:
6W = 48
Divide both sides by 6:
W = 8
The steel is 8 meters wide. The length is twice that minus 4 meters or 12 meters.
Check:
2(12) + 2(8) ?= 40
24 + 16 ?= 40
40 = 40 (answers are correct)