This is an ellipse.
Equation of an ellipse: 
Let's find the center point first. We can do this by finding out the midpoint between the vertices or the foci.
(-9+7)/2=-1
Center: (-1,3)
Now we need to find a and b (length along x and length along y).
We know "a". It is the distance between the center and the right or left bound.
a=7-(-1)=8
To find out "b", first see that...
b^2=a^2-(distance from center to foci)^2
foci distance=3-(-1)=4
b^2=8^2-4^2
b^2=64-16
b^2=48
b=4√3
answer: 
SORRY if its too late.
Proportions with variables:
let's look at an example from my homework hehe
.3:4=9:y
First, you change the ratios to fractions.
.3/4=9/y.
4 times 9 is 36. I multiplied the numerator of 9/y and the denominator of .3/4.
You also do this with the other numerators and denominators. .3 times y= 36. (Both equations have to equal the same number) if you don't know the answer, just do 36 divided by .3. The answer is 120.
y=120
Answer:
1008 in
Step-by-step explanation:
84x12=1008
84 feet times 12 inches because 12 inches is a foot.
so 84 feet times 12 inches gets your answer. 84 times 12=1008
make sense?
Answer: y = -3x/7 + 26/7
Step-by-step explanation: Using the "slope-intercept" format, we can set up 2 equations, using the given points.
The format: y = mx + b, where m is the slope and b is the y-intercept (where x = 0)
To find m and b, we need 2 equations which we get using the 2 given points:
(-3,5):
5 = m(-3) + b (equation 1)
(4,2):
2 = m(4) + b (equation 2)
Subtract #2 from #1 to get:
3 = -7m
m = -3/7
Then, using equation 1, find b:
5 = (-3/7)*(-3) + b
b = 5 - 9/7 = 26/7
The equation is then:
y = -3x/7 + 26/7
The force for the case 1 is 64 pounds and the distance is 9 feet, it is:
Now, if the force is 36 pounds, let solve for the distance:
Hence the answer is 12 feet.
