2) In terms of pi, what is the area of the circle defined by the equation 2x^2+2y^2+10x-6y-18=0
Divide every term by 2 and rearrange as
x^2 + 5x + y^2 - 3y = 9 complete the square on x and y
x^2 + 5x + 25/4 + y^2 - 3y + 9/4 = 9 + 25/4 + 9/4 factor and simplify
(x + 5/2)^2 + ( y - 3/2)^2 = 36/4 + 25/4 + 9/4
(x + 5/2)^2 + ( y-3/2)^2 = 70 /4 = 35 / 2 =17.5
The area = pi * r^2 = pi * 17.5 = 17.5 pi
