Which expression is equivalent to 8 + d^2 + 3?
GMAT Advanced Math : (Adv_Math) Questions
Which expression is equivalent to \(8 + \mathrm{d}^2 + 3\)?
1. TRANSLATE the problem information
- Given: \(8 + \mathrm{d}^2 + 3\)
- Find: Which expression is equivalent to this
2. INFER the approach needed
- I need to simplify this expression by combining like terms
- The constants 8 and 3 can be combined since they're both constant terms
- The \(\mathrm{d}^2\) term stays separate since it's not a constant
3. SIMPLIFY by combining like terms
- Rearrange for clarity: \(\mathrm{d}^2 + 8 + 3\)
- Add the constants: \(8 + 3 = 11\)
- Final simplified form: \(\mathrm{d}^2 + 11\)
Answer: B (\(\mathrm{d}^2 + 11\))
Why Students Usually Falter on This Problem
Most Common Error Path:
Weak SIMPLIFY execution: Students make basic arithmetic errors when adding \(8 + 3\), perhaps getting 5, 24, or other incorrect sums.
If they calculate \(8 + 3 = 5\), this leads them to \(\mathrm{d}^2 + 5\), making them select Choice C (\(\mathrm{d}^2 + 5\)).
Second Most Common Error:
Poor TRANSLATE reasoning: Students might misread the operation signs in the original expression, seeing subtraction where there's addition.
If they misread \(8 + \mathrm{d}^2 + 3\) as involving subtraction, they might work with incorrect terms and end up confused, leading to guessing among the remaining choices.
The Bottom Line:
This problem tests fundamental algebra skills - recognizing like terms and performing basic arithmetic accurately. Even though it looks simple, small errors in reading or calculation can easily lead to wrong answers.