Equation of a circle is (x-x1)+(y-y1)=r²
when x1 and y1 are the coordinates of the centre
So you can substitute the centre in to get (x-5)²+(y+9)²=r²
When you draw a diagram it's obvious the radius is 9
9²=81
Therefore equation is (x-5)²+(y+9)²=81
Any questions, just ask :)
Solve using system of equations!
Let y=total amount of money and x=hours of overtime.
mall: y=400+15x
movies: y=360+20x
Solve! Set the equations equal to each other to find x.
400+15x=360+20x
40=5x
x=8
After 8 hours of overtime the movies would pay her more.
Answer:
The rational number equivalent to 3.24 repeating is 321/99
Step-by-step explanation:
To convert the decimal number to a rational number we can state this number and its multiples of 10, trying to find two number with identical decimal parts:
n=3.24242424...
10n=32.4242424....
100n=324.2424242...
Now, 100n and n have the same decimal part, then by subtracting these numbers we obtain:
100n-n=324.24242424...-3.24242424... = 321
99n = 321
n = 321/99