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## DrPepperx3 Help with 2 questions? Medal(: one year ago one year ago

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1. DrPepperx3

7. Evaluate 1/2a^–4b^2 for a = –2 and b = 4. a. 2 b. 1/2 c. 3 d. 4 8. Is the following statement always, never, or sometimes true? A number raised to a negative exponent is negative. a. always b. never c. sometimes

2. jim_thompson5910

# 7 First simplify $\Large \frac{1}{2}a^{-4}b^{2}$ $\Large \frac{1}{2}\frac{1}{a^{4}}b^{2}$ $\Large \frac{b^2}{2a^{4}}$ Now plug in a = -2 and b = 4 $\Large \frac{(4)^2}{2(-2)^{4}}$ I'll let you finish

3. DrPepperx3

1/2 ?

4. jim_thompson5910

correct

5. DrPepperx3

K(: and what abput #8 ? I thought it was sometimes

6. jim_thompson5910

for #8, think about the following examples 2^(-3) (-4)^(-2) (-5)^(-3) (7)^(-4) Evaluate each and tell me what you get

7. DrPepperx3

2^(-3) = 1/8 (-4)^(-2) = 1/16 (-5)^(-3) = - 1/125 (7)^(-4) = 1/2401 ?

8. jim_thompson5910

perfect on all 4, what do you notice about the signs of each result

9. DrPepperx3

Well 1 is negative so i was right the answer is sometimes because the rest is positive

10. jim_thompson5910

correct, So when we say "A number (positive or negative) raised to a negative exponent is negative" is not always true (because you got 3 positive results out of 4), but it's not completely false either (you got 1 negative result out of 4) so that's why it's sometimes true

11. DrPepperx3

Ohhh Ty !

12. jim_thompson5910

you're welcome