Solve the following equations 19=7+y

Solve the given system of equations. 2y= -x+9 , 3x-6= -15

Which one ? is the answer and how to find this answer

Tyler enjoys the fish so much that after his birthday his family decides to take him to a famous aquarium a tank at the aquarium is similar to his tank with the scale factor of 8 how many times greater is the volume of the tank at the aquarium than the volume of tyler tank