\(10-(\mathrm{n}+4)=3\) What value of n is the solution to the given equation? -{3} 3 11 9...
GMAT Algebra : (Alg) Questions
\(10-(\mathrm{n}+4)=3\)
What value of n is the solution to the given equation?
- \(-3\)
- \(3\)
- \(11\)
- \(9\)
1. INFER the solution strategy
- We have a linear equation with parentheses: \(\mathrm{10-(n+4)=3}\)
- Strategy: First distribute the negative sign, then combine like terms, then isolate the variable
2. SIMPLIFY by distributing the negative sign
- \(\mathrm{10-(n+4)}\) becomes \(\mathrm{10-n-4}\)
- Remember: The negative sign applies to everything inside the parentheses
- Our equation is now: \(\mathrm{10-n-4=3}\)
3. SIMPLIFY by combining like terms
- On the left side: \(\mathrm{10-4=6}\)
- Our equation becomes: \(\mathrm{6-n=3}\)
4. SIMPLIFY to isolate the variable term
- Subtract 6 from both sides: \(\mathrm{6-n-6=3-6}\)
- This gives us: \(\mathrm{-n=-3}\)
5. SIMPLIFY to solve for n
- Since we have \(\mathrm{-n=-3}\), multiply both sides by -1
- Final result: \(\mathrm{n=3}\)
Answer: B) 3
Why Students Usually Falter on This Problem
Most Common Error Path:
Weak SIMPLIFY execution: Sign error when distributing the negative sign
Students often write \(\mathrm{10-(n+4)}\) as \(\mathrm{10-n+4}\) instead of \(\mathrm{10-n-4}\). They forget that the negative sign must be distributed to both terms inside the parentheses.
Following this error path:
\(\mathrm{10-n+4=3}\)
\(\mathrm{14-n=3}\)
\(\mathrm{-n=-11}\)
\(\mathrm{n=11}\)
This may lead them to select Choice C (11)
Second Most Common Error:
Weak SIMPLIFY execution: Forgetting the final step to solve for n
Students correctly work through the problem until they reach \(\mathrm{-n=-3}\), but then stop or incorrectly think this means \(\mathrm{n=-3}\). They forget to multiply both sides by -1 to get the positive value of n.
This may lead them to select Choice A (-3)
The Bottom Line:
This problem tests careful execution of algebraic procedures, particularly managing negative signs. Success requires systematic application of distribution and solving techniques without rushing through the sign changes.