What is the solution to the system of equations y= -3x+6 y=9
a (-21,9)
b (9,-21)
c (-1,9)
d (9,-1)

Can some one me with this math problem?

Acollege is planning to construct a rectangular parking lot on land bordered on one side by a highway. the plan is to use 680 feet of fencing to fence off the other three sides. what dimensions should the lot have if the enclosed area is to be a maximum?

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 - 4x - 5 = 0