Question

If x and y are positive integers and 3x+5y = 18 what is value of x? the answer is 1. Can you explain why?

Answer 1

You may be able to figure itmout if you make a table of values for x and y
When x =1, y =3
when x = 2, y = 2.4
When x = 3, y =1.8
When x = 4, y= 1.2
when x = 5, y = 0.6
when x=6 , y = 0
the only solutions which give both x and y as positive integers are for x = 1 therefore this is the only possible answer