Answer:23
Step-by-step explanation:
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: 
Elvira (e) is 5 years older than Morton (m)
e = m + 5
Morton (m) is twice as old as Michelle (c)
m = 2c
The combined total of their ages is 85
e + m + c = 85
We want m at the end so let's write everything in terms of m.
e = m + 5
c = m/2
85 = e + m + c = m+5 + m + m/2 = 5 + (5/2) m
m = (2/5) (85 - 5) = 32
Answer: 32 years old
Check:
That makes Elvira 37 and Michele 16, total 32+37+16=85, good