What is the sum of the roots of x^2 - 5x + 4 = 0?
Answer and explanation
Correct answer: C. 5
- Step 1: For ax^2 + bx + c = 0 the sum of the roots is -b/a. Step 2. Here the sum is 5. Answer: 5. Why not the others: 4: That is the product of the roots. -5: That has the wrong sign: the sum of the roots is -b/a, which is +5 here. 3: That is the difference of the roots.
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