So we are given a system: Substitute x = 2 we get the system: Multiply the first equation by -5 and the second by 2 we get the system: Adding the two equations we get : We find the value of y by using any of the other equations like this: Final solution:
Multiples of 15 are: 15,30,45,60,75,90,105,120,135,150,165,180,195,210,225,240,255,270,285,300,315,330,345,360,375,390,405,420,435,450,465,480,495,510,525,540,555,570,585,600,615,630,645,660,675,690,705,720,735,