PLZZ HELP ME WITH THIS

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.

The result of which expression will best estimate the actual product of (-4/5) x (3/5) x (-6/7) x (5/6) (i need an expression not an answer)

Simplify the imporper fraction 31/2