How do you convert a fraction into a whole number?

I am doing a math worksheet regarding writing linear equations and I have to rewrite six equations in standard form which is Ax+Bx=C. A couple of rules for re-writing an equation into standard form is that Ax cannot be a fraction nor a negative number. Only a whole positive number.
My question is how to convert a fraction into a whole number so that I can solve the equations which involve a fraction. I am aware that if the fraction can be simplified (such as 9/3), it can become a whole number (3). I want to know how to convert a fraction which cannot be simplified into a whole number.
Thanks; and I am sorry about the lengthy explanation. I just want to be specific.