ISEE Word Problems Question 239: Answer and Explanation
Home > ISEE Test > ISEE Word Problems Practice Tests
Test Information
- Use your browser's back button to return to your test results.
- Do more ISEE Word Problems Practice Tests.
Question: 239
3. If k is a positive integer, and (x + 11)2 = x2 + kx + 121, what is the value of k ?
- A. 121
- B. 55
- C. 22
- D. 11
Correct Answer: C
Explanation:
The answer is C
Use FOIL (First, Outside, Inside, Last) on the two factors: (x + 11)(x + 11) = (x2 + 11x + 11x + 121). Combine like terms: x2 + 22x + 121. Thus, k = 22.
Plug in a number for x, such as 2, and solve both sides of the equation: 132 = 4 + 2k + 121, 169 = 125 + 2k. Combine like terms and divide by 2: k = 22.