The square of a certain negative number is equal to five more than one-half of that number. what is the number?

Which of the following system of equation is not equal to the system of equations is not equal to the system of equations shown below

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

If the endpoints of the diameter of a circle are (8, 6) and (2,0), what is the standard form equation of the circle? a) (x + 5)2 + (y + 3)2 = 18 (x + 5)2 + (y + 3)2 = 3.72 (x - 5)2 + (y - 3)2 = 18 d) (x - 5)2 + (y - 3)2 = 32