Find the center coordinate of the circle: X & # 178; + Y & # 178; - 2x + 4y-11 = 0, and the radius is

Find the center coordinate of the circle: X & # 178; + Y & # 178; - 2x + 4y-11 = 0, and the radius is

x²+y²-2x+4y-11=0
(x²-2x+1)+(y²+4y+4)=16
(x-1)²+(y+2)²=4²
Center coordinates (1, - 2), radius 4

Find the general equation of the circle with radius 5 and the center of the circle X & # 178; + Y & # 178; + 2x-6y + 1 = 0

(x + 1) ² + (Y-3) ² = 25 expand it
How do you type your superscript?

What are the center coordinates and radius of the circle X & # 178; + Y & # 178; + 2x-6y + 9 = 0?

∵（X+1)^2+(Y-3)^2=1
∴（-1,3）,R=1

The teacher gave such a question: given x + 5Y = 6, find the value of X & # 178; + 5xy + 30y, evaluate the whole!

x+5y=6
Original formula = x (x + 5Y) + 30y
=6x+30y
=6(x+5y)
=6×6
=36