The general form for the equation of a circle is shown.

[tex]\[ 3x^2 + 3y^2 + 30x - 24y - 12 = 0 \][/tex]

What is the standard form of the equation?

Type the correct answer in the box. Use numerals instead of words.

[tex]\[ (x + \square )^2 + (y + \square )^2 = \square \][/tex]



Answer :

To convert the general form of the equation of a circle to its standard form, follow these steps:

1. Start with the given equation:
[tex]\[ 3x^2 + 3y^2 + 30x - 24y - 12 = 0 \][/tex]

2. Divide every term by 3 to simplify the equation:
[tex]\[ x^2 + y^2 + 10x - 8y - 4 = 0 \][/tex]

3. Rewrite the equation grouping the [tex]\( x \)[/tex] and [tex]\( y \)[/tex] terms together:
[tex]\[ x^2 + 10x + y^2 - 8y = 4 \][/tex]

4. Complete the square for the [tex]\( x \)[/tex] terms:
[tex]\[ x^2 + 10x = (x + 5)^2 - 25 \][/tex]

5. Complete the square for the [tex]\( y \)[/tex] terms:
[tex]\[ y^2 - 8y = (y - 4)^2 - 16 \][/tex]

6. Substitute these completed squares back into the equation:
[tex]\[ (x + 5)^2 - 25 + (y - 4)^2 - 16 = 4 \][/tex]

7. Simplify the equation by combining constants:
[tex]\[ (x + 5)^2 + (y - 4)^2 - 41 = 4 \][/tex]

8. Add 41 to both sides to isolate the perfect squares on the left-hand side:
[tex]\[ (x + 5)^2 + (y - 4)^2 = 45 \][/tex]

The standard form of the equation for the given circle is:
[tex]\[ (x + 5)^2 + (y - 4)^2 = 45 \][/tex]

So in the formatting desired,
[tex]\[ (x + 5)^2 + (y + (-4))^2 = 45 \][/tex]

Therefore:
[tex]\[ (x+5)^2 + (y-4)^2 = 45 \][/tex]