If 7 boxes of energy bars cost $6.75 more than 4 boxes of energy bars, how much doeseach box cost? how would i set this equation up

Find the solution of this system of equation -7x+y=-20 9x-3y=36

Girardo is using the model below to solve the equation . girardo uses the following steps: step 1 add 4 negative x-tiles to both sides step 2 add 1 negative unit tile to both sides step 3 the solution is which step could be adjusted so that gerardo's final step results in a positive x-value? in step 1, he should have added 4 positive x-tiles to both sides. in step 1, he should have added 3 negative x-tiles to both sides. in step 2, he should have added 4 negative unit tiles to both sides. in step 2, he should have added 1 positive unit tile to both sides.

Kira looked through online census information to determine the overage number of people living in the homes in her city what is true about kira's data collection?