The sum of two numbers is 42 and their difference is 4. find the number

Sam makes his sales calls according to a pattern. he travels either north or south depending on the calendar. some of his past trips were as follows: on february 17, april 24, june 10, september 19, and november 3 he drove north. on february 28, may 25, august 22, november 20, and december 18, he drove south. describe sams' pattern. in which direction will sam drive on oct4 and oct 24?

One of the same side angles of two parallel lines is 20° smaller than the other one. find the measures of these two angles.

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).