which terms could be used as the last term of the expression below to create a polynomial written in standard form? check all that apply.

–5x2y4 + 9x3y3 +

x5

y5

–4x4y5

6x4y

–xy5

–x4^-9

why doesn't anybody answer?

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?