How to do growing patterns in math​

7. if the value of x varies directly with the value of y, and x = 3 when y = 21. what is the valu y, and x = 3 when y = 21. what is the value of x when y = 105?

Which ordered pair is a solution to the system of linear equations? 2x + 3y= 6 –3x + 5y = 10

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