Advanced Math practice question

Answer: A. (x + 7)(x − 2)

Look for two numbers that multiply to −14 and add to +5: they are +7 and −2. So x² + 5x − 14 = (x + 7)(x − 2). Check: 7x − 2x = 5x and 7 × (−2) = −14.

Why the other answers are wrong

B. (x − 7)(x + 2)

The signs are flipped. (x − 7)(x + 2) gives a middle term of −7x + 2x = −5x, not +5x.

C. (x + 14)(x − 1)

14 and −1 do multiply to −14, but they add to +13, so this expands to x² + 13x − 14.

D. (x + 7)(x + 2)

7 and 2 add to 9 and multiply to +14: this expands to x² + 9x + 14. Both the middle term and the sign of the constant are off.

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