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Substitute the given values to the given equation. The one which gives a false statement is not a solution.
C
To check which of the given values is not a solution to x^3-3x^2-25x+75=0, we will substitute them to the given equation and check which one gives a false statement. Let's start by substituting 5 for x.
x= 5
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The result is a true statement, so 5 is indeed a solution of the given equation. Now we will check x=3.
x= 3
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We found that 3 is also a solution, so let's try the third possibility, x=- 3.
x= - 3
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The result is a false statement, so - 3 is not a solution of the given equation. To make sure that we are right, we will check the last option, x=- 5.
x= - 5
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We found that 3, 5, and - 5 are the solutions of x^3-3x^2-25x+75=0, but - 3 is not a solution. Therefore, the correct option is C.