Which one doesn't belong?

1. a right triangle is graphed on a coordinate plane. find the length of the hypotenuse. round your answer to the nearest tenth. 2. use the angle relationship in the figure below to solve for the value of x. assume that lines a and b are parallel and line c is a transversal.

Average acceleration: i have no idea how to do this.

Which expressions equal 9 when x=4 and y=1/3 a. x2+6y b. 2x + 3y c. y2-21x d. 5 (x/2) -3y e. 3x-9y