I need help with my math please help ASAP.

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

The mean finish time was 185.52 with a standard deviation of 0.327 minute. the winning car driven by chris finished in 185.13. the previous year race had a mean finish time of 110.3 with a standard deviation of 0.106. the winning car that year driven by karen finished in 110.13 minutes. find their respective z-scores. chris - z-score karen “- z-score

50 points~ ! i have to turn this in tomarrow