In terms of pi, what is the area of the circle defined by the equation $2x^2+2y^2+10x-6y-18=0?
Isolate the constant: 2x2+2y2+10x−6y=18
Divide the entire equation by 2: x2+y2+5x−3y=9
Add 8.5 to both sides so we can complete the square for both x and y: x2+y2+5x−3y+8.5=17.5
Complete the square: (x+2.5)2+(y−1.5)2=17.5
Note the constant on the left-hand side equals the radius of the circle squared, meaning the area of the circle is 17.5π