Question 1207410
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Ignore the absurd response from tutor @MathLover1.  "[16,-8]" is not correct notation for any interval....<br>
For the given function f(x), the function is defined when x is between -8 and 4.<br>
So for the function f(-2x), the function is defined when -2x is between -8 and 4 -- which is between -8/-2 = 4 and 4/-2 = -2.  Then of course you need to write the answer in interval notation with the smaller number first.<br>
ANSWER: [-2,4]<br>