Can u help me with the math problems plz ?

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?

What is the difference between –12 and –5? what is the distance between –12 and –7 on a number line? units

Which expression has a negative value? 2+12 (-) ) -35-5