X^2+3y-4+2(x-z) when x=7 y=5 and y=-3

7^2 + 3(5) - 4 + 2(7- -3)
49 + 15 - 4 + 2(10)
49 + 15 - 4 + 20
80

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.