Answer:
The Pythagorean Theorem, a2+b2=c2, a 2 + b 2 = c 2
I dont know the exact positions to put the lengths, but tell me if this helps!
If Gina's age is x and Abigail is younger than Gina, Abigail's age will be represented by x-1 given that their ages are consecutive integers.
Translating the fact that the the difference of the square of Gina's age and eight times Abigail's age is 17, we will have the following equation:

We can use the equation above to find Gina's age.
Answer:
x - 7/9 = f(x)^-1
Step-by-step explanation:
f(x) = 9x + 7
y - 7 = 9x
y - 7/9 = 9x/9
Interchange!
x - 7/9 = y
Recall your d = rt, distance = rate * time
so... one train goes west and the goes the opposite way... alrite... so... notice, by the time 338 miles have been covered by both, it will have been "t" hours, and whatever "t" is, is the same amount of time the westbound train has been running as well as the eastbound train has been running.
now, let's say, since by "t" hours they've covered 338 altogether, so, if the westbound train has covered say "d" miles, then the eastbound train would have covered the slack from 338 and d, that is, "338 - d".

so, 2hours and 36 minutes.