25 points! Help (Vectors)

Adj has a total of 1075 dance and rock songs on her system. the dance selection is 4 times the size of the rock selection. write a system of equations to represent the situation.

Solve the following inequalities and show the solution on a number line. 3/4 (2x-7) ≤ 5

Atriangular field has sides of lengths 21, 39, and 41 yd. find the largest angle. (round your answer to the nearest degree.)