In terms of pi, what is the area of the circle defined by the equation 2x^2+2y^2+10x-6y-180=0?
+129847 Rewrite as
2x^2 + 10x + 2y^2 - 6y = 180 divide through by 2
x^2 + 5x + y^2 - 3y = 90 complete the square on x and y
x^2 + 5x + 25/4 + y^2 - 3y + 9/4 = 90 + 25/4 + 9/4
(x + 5/2)^2 + ( y - 3/2)^2 = 90 + 17/2
(x + 5/2)^2 + ( y - 3/2)^2 = 98.5 { 98.5 = r^2 }
So....the area =
98.5 pi
