Please help me i hate doing math work

Find an equation of the line perpendicular to the graph of 28x-7y=9 that passes through the point at (4,1)

Kayla and alberto are selling fruit for a school fundraiser. customers can buy small boxes of grapefruit and large boxes of grapefruit. kayla sold 3 small boxes of grapefruit and 1 large box of grapefruit for a total of $65. alberto sold 1 small box of grapefruit and 1 large box of grapefruit for a total of $55. what is the cost each of one small box of grapefruit and one large box of grapefruit?

Find the domain of the following expression: 1/(√x)-2