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Choose the inverse operation. The variable has subtracted from it, so adding isolates it. Adding the same number to both sides preserves the inequality's direction — only multiplying or dividing by a negative would flip it, and that never happens here.
Add 4 to both sides.
State the solution set. In interval notation , with excluded because the relation is strict.
Verify around the boundary. At : , and ✓ (inside). At : , and is false, so the endpoint is correctly open ✓. At : ✗ (outside). The raw inequality and agree at exact rational points ✓.
Note the shortcut. For the answer is always ; here ✓. Recognising the pattern turns the problem into a single addition, and it doubles as a check on the algebra.
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