ISEE Mathematics Achievement Question 7: Answer and Explanation
Home > ISEE Test > ISEE Mathematics Achievement Practice Tests
Test Information
- Use your browser's back button to return to your test results.
- Do more ISEE Mathematics Achievement Practice Tests.
Question: 7
7. If (x + 6)2 = x2 + nx + 36, what is the value of n?
- A. 3
- B. 6
- C. 12
- D. 36
Correct Answer: C
Explanation:
C
Use FOIL (First, Outside, Inside, Last) on the two factors: (x + 6)(x + 6) = (x2 + 6x + 6x + 36). Combine like terms: x2 + 12x + 36. Thus, n = 12.
Plug in a number for x, such as x = 2, and solve both sides of the equation: 82 = 4 + 2n + 36, so 64 = 40 + 2n. Combine like terms and divide by 2: n = 12.