Ill give brainlest .. just need help .

Ineed here’s a picture of the question

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.

How do i i solve this equation? -18 = x/3 + 3