One number is seven more than twice another. if their sum is decreased by ten, the result is twelve. find the numbers

The numbers are 5 and 17. 17 is 7 more than two of 5, (or 10) and 5+17-10=12

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.