Factorize X2 plus 9x plus 20 equals?

Answer 1

x2+9x+20 We need two brackets, each with x at the beginning. (x ) (x ) Since the 20 is positive, I know the two numbers that multiplied to 20 must have had the same sign (two negatives make a positive, two positives make a positive) Also since the middle term is positive, I know that the two numbers must have been positive as well. So our brackets are (x + ) (x + ) That leaves me with the question - what two numbers multiply to 20 and have a sum of 9 (the coefficient of x) (x + 5) (x + 4)

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The first answer is the best! its the easiest way to find the answer out. It helped me practice for my test :]

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