1. 3x - 2y = 8 Subtract 3x on both sides
-2y = 8 - 3x Divide by -2 on both sides to get y by itself
y = -4 + 3/2x
2. a + b / 3 = 5 Multiply 3 on both sides
a + b = 15 Subtract a on both sides to get b by itself
b = 15 - a
3. 12x - 4y = 20 Subtract -12x on both sides
-4y = 20 - 12x Divide -4 on both sides to get y by itself
y = -5 + 3x
4. y + 3 = -5(x - 2) Multiply -5 to (x-2)
y + 3 = -5x + 10 Subtract 3 on both sides to get y by itself
y = -5x + 7
1/9 on a calculator is 0.11111111
Answer:
(x + 4)^2 + (y - 8)^2 = 81
or
(x + 4)^2 + (y - 8)^2 = 9^2 depending on how your teacher wants it written.
Step-by-step explanation:
The standard form for a circle is
(x + h)^2 + (y + k)^2 = r^2
r is the radius.
You are given the diameter
r = d/2
r = 18/2
r = 9
So you already have the right hand side of the equation
(x + h)^2 + (y + k)^2 = 9*2
(x + h)^2 + (y + k)^2 = 81
You basically have h and k as well. They come from the center point.
h = 4
k = - 8
So the equation of the circle (and the answer) is
(x + 4)^2 + (y - 8)^2 = 81
One question remains. Why do the x and y values change signs? If you know what the distance formula is, then what you are finding is the distance r of all points on the circle from the center of the circle.
It is the distance formula that is actually the formula for the circle.
Answer:
all you need to do is to multiple
