<PRE><B>Question 169927</B>
.
Let w = width of aluminum
then
2w = length of aluminum
.
Box AFTER the square is cut:
width = w-5-5 = w-10
length = 2w-5-5 = 2w-10
.
Volume of box:
10500 = (w-10)(2w-10)5
2100 = (w-10)(2w-10)
2100 = (w-10)2(w-5)
1050 = (w-10)(w-5)
1050 = w^2-5w-10w+50
1050 = w^2-15w+50
0 = w^2-15w-1000
.
Factoring the right:
0 = (w+25)(w-40)
.
w = {40, -25}
.
We can toss out the negative solution leaving us with:
w = 40 cm (width of rectangle)
.
length of rectangle:
2w = 2(40) = 80 cm (length of rectangle)</PRE>