Algebramedium · Past Paper
If 1/x + 1/y = 5 and 1/x - 1/y = 1, find 1/x.
A3
B2
C6
D4
✓ Correct Answer: A — 3
Let u = 1/x and v = 1/y. u+v=5, u-v=1. Adding them gives 2u=6, so u=3. Thus 1/x = 3.
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