What is the larger root of x^2 + 2x - 8 = 0?
Answer and explanation
Correct answer: C. 2
- Step 1: Find two numbers with product -8 and sum -2: they are 2 and -4. Step 2. The equation factorises as (x - 2)(x + 4) = 0. Step 3. The roots are x = 2 and x = -4, so the larger is 2. Answer: 2. Why not the others: -4: That is the smaller root. -2: The sign is wrong: if (x - r) is a factor, the root is +r. 4: That is the smaller root with its sign reversed.
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