Hello!
To solve this, first compare the two volumes.
Let's start by first finding the volume of 5*7*12 (length*width*height) which would be 420 cm^3.
Now, find the volume of (5*2)*(7*2)*(12*2) or 10*14*24. This would simplify to 3,360 cm^3.
Now notice, when you double each side, you are basically doing 420*2^3 and 2^3 simplifies to 8. Therefore, when you double the sides, you are multiplying the entire volume of the original dimensions by 8.
