Final answer:
To find the missing values in the simplified expression, we combine like terms and rearrange the expression.
Step-by-step explanation:
To fill in the missing values of the expression -3 -x + 9 -3x, we need to combine like terms. The like terms in this expression are the terms with the same variables and exponents. In this case, we have -x and -3x. When we combine these terms, their coefficients should be added together. So, -x + (-3x) is equal to -4x.
Now, let's rearrange the expression so that the terms with x are grouped together and the constant terms are grouped together. The given expression can be rewritten as -x - 3x + 9 - 3. Combining the like terms, we have -4x + 6. Therefore, the missing values of the simplified expression are -4x + 6.
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