Answer: choice C) x+4
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Step-by-step explanation:
The middle term is 14x which has coefficient 14. The last term is 40. The two numbers that multiply to 40 and add to 14 are 10 and 4. Note how
10+4 = 14
10*4 = 40
So because of that, this means x^2+14x+40 factors to (x+4)(x+10). The order of the factors does not matter. The two factors are x+4 and x+10.