If n is "the number," which equation could be used to solve for the number?

Find the image of a(4, -2) after it is reflected over the line y= 2, then reflected over the line x = 2. (-8,6) o (0.-2) o (0,6) (-8, -2)

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.