The Taieri Plain in New Zealand is 6 feet below sea level (or -6 feet). If you are standing 3 feet above sea level, is your elevation the opposite of the elevation of the plain? Describe the steps you would follow with a vertical number line to find the answer.

step-by-step explanation:

step 1: solve one of the equations for one of the variables. let's solve the first equation for y:

step 2: substitute that equation into the other equation, and solve for x.

step 3: substitute x = 4 x = 4 x=4 into one of the original equations, and solve for y.