Let P = (-2,4). a. Line r is horizontal and passes through P. Write an equation for r.

b. Line s is vertical and passes through P. Write an equation for s.

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.