A rectangular piece of metal is 15 inches longer than it is white squares with size 3 inches longer cut from the four corners and the flaps are for the upward to form an open box if the volume of the box is 750 inches^3 What were the original dimensions of the piece of metal?

What is the original width in inches?
What is the original length in inches?

1 answer

"white squares with size 3 inches longer" longer than what? I'll assume you meant "3 inches long"
Let the metal be x by x+15
So the volume
3(x-6)(x+15-6)=750
x = 16
So the metal was 16 by 31