Using the substitution method, solve for x and y in the following system of equations.
y-4x=16
12x-y=-24

Does the point (1, sqrt 7) lie on circle shown.

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

Sasha delivers newspapers to subscribers that live within a 4 block radius of her house. sasha's house is located at point (0, -1). points a, b, c, d, and e represent the houses of some of the subscribers to the newspaper. to which houses does sasha deliver newspapers?