Rectangular tank A, measuring 8 in long, 5 in wide and 7 in high, is full of water. Tank B is a cube with sides 5 inches, and it is empty. If the water is poured from tank A into tank B until it is filled up, how much water will be left in tank A? cubic inches.

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.

The answer should be 5.

The principal, real, root of: 50−−√2=7.071067817.07106781−7.0710678150 is not a perfect square