What's the value of x and y when 4x+y=210 and 3x+2y=195?

After substitution method, I got x=45 and y=30

You already hve the answer, but you do this by turning the equation into standard form. Since we are isolating y for each linear equation, we must first subtract the 4x and 3x on both sides. This should come out to y=-4x+219 and 2y=-3x+195. Since we have our first equation in standard form, all we have go do is divide 2 on both sides frome the second equation. Then you can solve by substitution (y=y)

These are the multiples of 15 but what you are probably asking or what are the factors of 15