Factorize completely the quadratic expression: x^2 - 7x + 12.
Answer and explanation
Correct answer: C. (x - 3)(x - 4)
- Step 1: Find two numbers whose product is +12 and whose sum is -7. Step 2. The numbers are -3 and -4 because (-3)(-4) = 12 and (-3) + (-4) = -7, giving (x - 3)(x - 4). Answer: (x - 3)(x - 4). Why not the others:* (x - 2)(x - 6) sums to -8; (x + 3)(x + 4) sums to +7; (x - 1)(x - 12) sums to -13.
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