We are asked to find the volume of the smaller prism, and we know that the larger prism has a volume of 2400 cubic feet. We also know that the scale factor of the two prisms is 1:4. You may be tempted to set 1/4 equal to x/2400, but that is not what you should do. Remember that the volume ratio is , if the similarity ratio is a/b. Now, with this in mind, we know that the cube root of 2400 is 13.388659. Now, we can set 1/4 equal to x/13.388659. Solve for x by cross multiplying. 13.388659=4x. Divide both sides by 4. x=3.34716475. Then, we need to find the volume of the smaller prism, so we find the third power of x, or 3.34716475, which is approximately 37.5, which is your solution.
first, you combine the terms together to get -7x^-1. you cant have negative exponents in the numerator so you move the x^-1 to the denominator. once it move its becomes positive then.