Please help, quickly if possible

Due to financial difficulties the owner of 4 skateboard stores is going to close 2 of his stores. based on the money earned at each store, which two stores should remain open?

Typically a point in a three dimensional cartesian coordinate system is represented by which of the following answers in the picture !

Will mark 50 show all what is the solution to the system of equations? use the substitution method and show your work. -5x+y= -3 -15 x+3y=7 explain what your answer in part (a) tells you about the association of the lines in this system.