Help me please! I don’t understand

The class wants to raise a total of $750.if they receive a profit of $1.25 from each candybar sold, how many bars must they sell to reachtheir goal

Terri makes a quilt using three sizes of fabric squares the side lenght of each fabric square is the square root of the area

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.