Answer:
3
Step-by-step explanation:
I think the easiest way to go about this is to choose on of the answers and fill it in to see if it's correct. Since you only have 4 possible answers, there's no need to actually solve this.
In the question it already tells us that x does not equal 0, so that answer is automatically not correct. Now your down to three possible answers.
Start with -3. First, fill in the x with -3 for what the equation is supposed to equal. That gives you 3/-3. Simplified, that is -1. Now put -3 in for the x in the equation. That gives you 3/2(-3) + 1/2. After running that through your calculator or solving it, you end up with 0. So -3 is not your answer.
Next we'll try the 2. Do as we did last time, and fill in the x on the answer part of the equation. You now have 3/2. That doesn't simplify so it stays as is. Now for the equation. That makes it 3/2(2) +1/2. Put that in your calculator or solve, and you get 5/4. 5/4 does not equal 3/2 so 2 is not your answer.
That leaves 3. You can go ahead and run through the steps above using 3 if you want to double check, but since it's the only answer left, there isn't really a need to.
Hope this helps :)
4963.32 is the answer your looking for man.
Square the top and the bottom. To get 7/11.
R = speed in still water
r + c = speed with current
r - c = speed against current
3.5(r + c) = 70
r + c = 20
c = 20 - r
4(r + c) = distance from pier to pier
5(r - c) = distance from pier to pier
4(r + c) = 5(r - c)
4(r + 20 - r) = 5(r - 20 + r)
80 = 10r - 100
180 = 10r
18 = r
The speed in still water is 18 km/hour