What is 0.917 in expanded form

Which represents the solution set of the inequality 5x-9 < 21? a. x < 12/5 b. x > 12/5 c. x > 6 d. x < 6

Prove that quadrilateral is a rhombus.

Find the vertex for the parabola given by the function ƒ(x) = −3x2 − 6x.