Which two expressions are equivalent

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

Ian is in training for a national hot dog eating contest on the 4th of july. on his first day of training, he eats 4 hot dogs. each day, he plans to eat 110% of the number of hot dogs he ate the previous day. write an explicit formula that could be used to find the number of hot dogs ian will eat on any particular day.

The ratios of boys to girls on a soccer league is 2: 5. if there are 28 boys, how many girls are playing soccer? extra points! will mark as brainiest asap