Solve the equation:
5 3
x – —— = – ——
7 7
5
Add —— to both sides, so you get x isolated at the left-hand side:
7
5 5 3 5
x – —— + —— = – —— + ——
7 7 7 7
3 5
x = – —— + ——
7 7
Now, add those fractions at the right-hand side of the equation:
– 3 + 5
x = —————
7
2
x = —— <——— this is the answer (first option: 2/7).
7
I hope this helps. =)