What is the radius of a circle whose equation is x2+y? +8x-6y+21=0?
2 units
3 units
4 units
5 units

  2 units

Step-by-step explanation:

Completing the squares for the x- and y-terms, we get ...

  (x^2 + 8x) +(y^2 -6y) = -21

  (x^2 +8x +16) +(y^2 -6y +9) = -21 +16 +9

  (x +4)^2 +(y -3)^2 = 2^2

Compare this to the standard form equation for a circle:

  (x -h)^2 +(y -k)^2 = r^2

and we see that the radius (r) is 2.

Step-by-step explanation:

The given equation is

To find the radius of the circle, we have to complete the squares for both variables, that would give us the explicit form, through which we can determine the radius.

So, according to this result the radius is 2, because the explicit expression of a circle states:

Where the right part of the equation is the square power of the radius.

Therefore, the radius is 2 units.

answer set (b) 0.5, 3/4 80% is in order from least to greatest.  

step-by-step explanation:

in order to compare rational numbers to each other, it is much easier if they are in the same form.   typically, the best form in which to evaluate rational numbers is in decimals.   in order to convert a percent to a decimal, you would divide the given percentage by 100.   you can also accomplish the conversion by moving the decimal point over two places to the left.   for example, the decimal value of 80% is 80/100, or 0.8.   in order to convert a fraction to a decimal, you need to divide the numerator by the denominator.   for example, 3/4 is 0.75.   so, for choice (b) 0.5 3/4 (0.75), 80% (0.8) is the only choice in which the numbers are in order from least to greatest.  

show us the graphs dude

step-by-step explanation: