Question

Please answer asap!!!!!

Answer 1

Step-by-step explanation:

The equation of a circle can be the expanded form of

\large \text{$(x-a)^2+(y-b)^2=r^2$}(x−a)

2

+(y−b)

2

=r

2

where rr is the radius of the circle, (a,\ b)(a, b) is the center of the circle, and (x,\ y)(x, y) is a point on the circle.

Here, the equation of the circle is,

\begin{gathered}\begin{aligned}&x^2+y^2+10x-4y-20&=&\ \ 0\\ \\ \Longrightarrow\ \ &x^2+y^2+10x-4y+25+4-49&=&\ \ 0\\ \\ \Longrightarrow\ \ &x^2+y^2+10x-4y+25+4&=&\ \ 49\\ \\ \Longrightarrow\ \ &x^2+10x+25+y^2-4y+4&=&\ \ 49\\ \\ \Longrightarrow\ \ &(x+5)^2+(y-2)^2&=&\ \ 7^2\end{aligned}\end{gathered}

⟹

⟹

⟹

⟹

x

2

+y

2

+10x−4y−20

x

2

+y

2

+10x−4y+25+4−49

x

2

+y

2

+10x−4y+25+4

x

2

+10x+25+y

2

−4y+4

(x+5)

2

+(y−2)

2

=

=

=

=

=

0

0

49

49

7

2

From this, we get two things:

\begin{gathered}\begin{aligned}1.&\ \ \textsf{Center of the circle is $(-5,\ 2)$.}\\ \\ 2.&\ \ \textsf{Radius of the circle is $\bold{7}$ units. }\end{aligned}\end{gathered}

1.

2.

Center of the circle is (−5, 2).

Radius of the circle is 7 units.

Hence the radius is 7 units.