Subtract 300 from both sides, which gives you -350= -X. Divide by -1 and get x=350. His bills were 350 dollars, which can be stated using the equation I put in the answer.
24 is the total number of kids in her class, and the 15 is the PART of the Whole number of kids in her class that are girls. hope this helps, please mark me brainliest thanks !