Work Step by Step
Replace $x$ with 1 and $y$ with -18 in $2x-y$: $2x-y=2\times(1)-(-18)=2+18=20$
You can help us out by revising, improving and updating this answer.Update this answer
After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.