What are the solutions of the equation x2 – 16x + 91 = 0?

Which equations represents circles that have a diameter of 12 units and a center that lies on the y-axis? check all that apply

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?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.