Recall your d = rt. distance = rate * time.
let's say the speed of the current is "c".
keeping in mind that, when the boat is going against the current, the boat is not really going at 2kmh, but instead at " 20 - c ", because the current is subtracting speed from it.
Likewise when is going with the current, is going at a speed of " 20 + c ".
if the boat took say "t" hours on the way over, on the way back it took the slack from the whole 8 hours and "t", namely it took " 8 - t " hours.

ration? You deserve better from your teacher.
The ratio of auditorium to theater seats is
1200:320
That's a perfectly valid answer and we could stop here if we weren't asked for lowest terms. Here I can see that 12 and 32 have a common factor of 4 and both these end in zero so 40 is a common factor:
1200:320 = 30:8
We can keep reducing by another factor of 2,
1200:320 = 30:8 = 15:4
There's our 15/4, which we get when we write the ratio as a fraction.
Answer: 15/4
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This question implies a ratio is just a fraction, which it isn't. Let's quickly note the differences.
A ratio can have zero on either side; 1:0 is a perfectly valid ratio but 1/0 is not a valid fraction. A ratio can't be all zeros -- that's not allowed.
A ratio can have more than two numbers. 3:4:5 is a common ratio that gives rise to a right triangle.
Like fractions, ratios can be reduced: For λ≠0,
λa : λb : λc = a:b:c
-3x+7
Step-by-step explanation:
The entire function f is being multiplied by -1, -1 isn't being plugged in for x in this case.
f -1(x)= -1(3x-7)
f -1(x)= -3x+7
what is your question lol