The slope would be 0.11x + 99 because they charge 0.11$ per mile and a starting fee of $99
The answer you should put is 9!
Use the Pythagorean Theorem OR the distance formula (they are based upon the same principles).
The x-component of this distance is the distance from -7 to +9, which is 16. If you're unsure of why, graph a number line, plot -7 and +9 and then count the number of scale divisions between the two.
The y-comp is the distance from 2 to 2, which is zero.
Thus, the distance between the two points is sqrt(16^2+0^2), or 16.
Formula for the area of a square = side^2
So, 15^2 will result in the area.
Thus, the answer is 225 mm^2 (when squaring, units are always given the square as well.)