Answer:
Equation of the circle =
80 = ( x - 1)^2 + (y + 1)^2
Step-by-step explanation:
Center = (1 , -1)
Point = ( 5 , 7)
Eqn of a circle is
r^2 = (x - h)^2 + (y - k)^2
We are not given the radius of the circle, fortunately we are provided the information that the circle contains a point ( 5, 7), so we use the above information to find r
Using the center (1, -1)
h - 1
k - -1
r^2 = (x - 1)^2 + ( y - -1)^2
r^2 = (x - 1)^2 + (y + 1)^2
With the point ( 5,7)
x = 5
y = 7
r^2 = ( 5 - 1)^2 + ( 7 + 1)^2
= 4^2 + 8^2
= 16 + 64
= 80
r^2 = 80
r = square root of 80
r = 8.94
The r = 8.94 , which means the equation of the circle is
80 = (x - 1)^2 + ( y + 1)^2
Changing the x from positive to negative, reflects the graph over the Y-Axis.
Adding 7 to X shifts the graph horizontally 7 units to the right.
Answer:
Step-by-step explanation:
Let Freda's sum = x
Donnie has 3/4 x
He spends 63 dollars. His sum is now
3/4x - 63
Now the equation looks like this
6(3/4x - 63) = x Remove the brackets
6*3/4 x - 378 =x
6 * 3/4 = 4 1/2
4 1/2 x - 378 = x Add 378 to both sides
4 1/2 x = x + 378 Subtract x from both sides
3.5 x = 378 Divide by 3.5
x = 378 /3.5
x = 108
Since x = 108, that's how much Freda had. (She spent nothing).
Putting both equations into standard form, we have the system
x -2y = 4
x -2y = -12
The lines these equations describe are
parallel.
