Write the equation of the line in slope-intercept form

On the first of each month, shelly runs a 5k race. she keeps track of her times to track her progress. her time in minutes is recorded in the table: jan 40.55 july 35.38 feb 41.51 aug 37.48 mar 42.01 sept 40.87 apr 38.76 oct 48.32 may 36.32 nov 41.59 june 34.28 dec 42.71 determine the difference between the mean of the data, including the outlier and excluding the outlier. round to the hundredths place. 39.98 39.22 0.76 1.21

I'll give brainliest if you answer right : )

50 will mark show all use the linear combination method to solve the system of equations. explain each step of your solution. if steps are not explained, you will not receive credit for that step. 2x+9y= -26 -3x-7y=13