Mckenna earns $12 per hour mowing her grandmother's yard what equation can i write

The physical fitness of an athlete is often measured by how much oxygen the athlete takes in (which is recorded in milliliters per kilogram, ml/kg). the mean maximum oxygen uptake for elite athletes has been found to be 60 with a standard deviation of 7.2. assume that the distribution is approximately normal.

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15

Which number completes the inequality? 2/3 < _ < 7/9