anonymous one year ago Evaluate the function rule for the given value. y = 15*3^x , for x = -3

1. anonymous

A) 5/3 B) 5/27 C) 135 D) 5/9

2. anonymous

3. anonymous

5/9

4. mathstudent55

y = 15*3^x , for x = -3 Replace x with -3. What do you get?

5. anonymous

You have $$15 \times 3^{-3}$$. In order to change the sign of an exponent, take the reciprocal, i.e. $$3^{-3} = \frac{1}{3^3}$$. So now you have$15\times 3^{-3} = 15\times \frac{ 1 }{ 3^3 } = \frac{15}{3^3}$Now, evaluate $$3^3$$, and simplify the fraction.

6. anonymous

15/27 @ospreytriple

7. anonymous

and then we simplify

8. anonymous

divide them by 3

9. anonymous

and we get 5/9

10. anonymous

I have about 2 same questions, I'll try to solve them and can u tell me if im right

11. anonymous

You are correct. Good job.