For the function f(x) = x + 7, what is the ordered pair for the point on the graph when x = 2b. a. ( 2b, 2b+7). b. ( 2b, x + 7). c.( x, x + 7 ). d. (x, 2b + 7)

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?