SOLUTION: An open box is formed from a rectangular piece of cardboard whose length is 8 cm more than its width by cutting squares whose sides are 2 cm in length from each corner and then fol

Algebra ->  Customizable Word Problem Solvers  -> Geometry -> SOLUTION: An open box is formed from a rectangular piece of cardboard whose length is 8 cm more than its width by cutting squares whose sides are 2 cm in length from each corner and then fol      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 1127975: An open box is formed from a rectangular piece of cardboard whose length is 8 cm more than its width by cutting squares whose sides are 2 cm in length from each corner and then folding up the sides. Find the dimensions of the box if its volume is
690 cm3.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+V+=+690+ cm3
Let +x+ cm = the width of the open box
+x+%2B+8+ cm = the length of the open box
+2+ cm = the height of the open box
+2x%2A%28+x+%2B+8+%29+=+690+
+x%5E2+%2B+8x+=+345+
complete the square
+x%5E2+%2B+8x+%2B+16+=+345+%2B+16+
+%28+x+%2B+4+%29%5E2+=+361+
+x+%2B+4+=+19+
+x+=+15+
and
+x+%2B+8+=+23+
------------------------
The dimensions are 15 cm x 23 cm x 2 cm
---------------------------------------
check:
+2%2A15%2A23+=+690+
+690+=+690+
OK