Question 738087: What is the factored expression of x^2+21x-100
Answer by josgarithmetic(39620)   (Show Source):
You can put this solution on YOUR website! Keep on using what you have been learning. What two numbers, integers, have product -100 and have sum +21?
Pick possibilities using the product 100.
10 and 10
5 and 20
4 and 25
2 and 50
One of the parts of the combination will need (most likely) to be negative and the other positive.
Look at 4 and 25. ONE of them must be positive and THE OTHER must be negative; but which?
-4+25= what?
4+(-25)=what?
(x_______)*(x_______)=x^2+21x-100
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