Question 1063302
perimeter = 2*width + 2*length, or the long way: width + width + length + length. In other words, all around the edge of the rectangle, what we call the perimeter.
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Length = 3W-7
So now we have: 
2W+2(3W-7) = 146 distribute the 2 over the "stuff" in the parenthesis (Distributive Property of Multiplication):
2W+6W-14 = 146
8W = 160
W = 20
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Check:
2(20)+2(3*(20)-7)
40+106 = 146 Correct
:
John