book Maths Puzzle Numerical Ability

Find all the values of x from the following equation:

30/2x+1 minus 8/x-1 + 2=0

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i'm not quite sure how to solve this using substitution.
3x-y=4
2x-3y=-9

Also, does the system have exactly one solution, or more?
Thanks for helping me! Mr X spent 2.5 hrs biking up a mountain. Rested for 30 minutes. Biked down in 1.5 hrs. How far did Mr. X bike, if his rate of ascent was 3 km/hr less than his rate of decent?