PLS HELP ME RN I AM FAILING AND NEED HELP ITS PYTHAGOREAN THEOREM

Find the rate of change for the situation.you run 7 miles in one hour and 21 miles in three hours.

The students at jefferson middle school are raising money for a charity by selling t-shirts and hats. the number of t-shirts sold was 3 times the number of hats. the profit was $5 for each t-shirt sold and $2.50 for each hat sold. the students raised $840 for the charity. they used the system below to analyze their success and found the solution to be (144, 48). 5x+2.50y=840 x=3y how much did they earn from t-shirt sales?

Tiene pendiente -4 y pasa por el punto (-3,-2) encuentre la ecuación de la recta