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Which choice is the appropriate simplified form and restriction for the variable? 3x^2+9x over x^2-2x-15

User Seabass
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2 Answers

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(3x^2 + 9x) / ( x^2 -2x -15)

Factor both polynomials

(3x)(x+3) / (x-5)(x+3) = 3x/(x+5)

The simplified form is 3x/(x+5)

The restriction for the variable is x ≠ -3 (this is because you can only simplify the factor x-3 if its value is not zero).

User Keidi
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If you would like to know what is the appropriate simplified form and restriction for the variable, you can calculate this using the following steps:

(3x^2 + 9x) / ( x^2 - 2x - 15) = (3x * (x + 3)) / ((x - 5) * (x + 3)) = 3x / (x - 5)

The simplified form is 3x / (x - 5) and the restriction for the variable would be x ≠ 5 and x ≠ -3.
User Pero
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