What is the difference between 8 and 18

8 is in the ones and 18 is in the tens

The numbers 18/0, 18/8 and 18/10 refer to the percentages of chromium and nickel in the stainless steel alloy. The "18" refers to the chromium content, which gives flatware its rust-resistance properties, and the "8" or "10" refers to the nickel content, which gives it its silver-like shine and some rust-resistance.

x+y=18

x-y=8

We can then use elimination to get just one variable.

 x+y=18

+x-y=  8

Which gives us:   2x=26

We then divide by 2 and get:    x=13

We next plug that into one of the two equations and solve for the other variable:    (13)+y=18

We subtract 13 from both sides and get:   y=5

So the two numbers are 13 and 5.