-3x + y is greater than -5

Tod does not have any cookies. david gives jeff 8 cookies. then he splits half of the cookies he has left with tod. david let’s c represent the number of cookies that he starts with. he finds the number of cookies that tod has is 1/2 the difference of c and 8. write an expression to represent the number of cookies that tod has.

You give a $4 tip for a meal that cost $22. approximately what percent of the bill was your tip?

Solve 3x-18=2y and 5x-6y=6 by elimination show work