## anonymous one year ago −4log2(n)−23=−19

1. UnkleRhaukus

first, add 23 to both sides

2. anonymous

(-4) -4log 2 (n)=42 (-4)

3. anonymous

oops not 42 but 4

4. UnkleRhaukus

type it again

5. anonymous

(-4) -4log 2 (n)=4 (-4)

6. UnkleRhaukus

what are the (-4)'s doing? you don't need them

7. anonymous

-4log 2 (n)=4

8. anonymous

sorry i thought you multiple both sides

9. UnkleRhaukus

Good, now divide both sides by -4

10. anonymous

how do you know how to divide vs multiple?

11. anonymous

log 2 (n)=-1

12. UnkleRhaukus

well the left hand side has $\color{blue}{-4}\log_2 (n)=4$ to get red of this on the left hand side, we need to apply inverse operation i.e. we need to divide by $$\color{blue}{-4}$$

13. UnkleRhaukus

to get rid*

14. UnkleRhaukus

this is like when we had $−4\log_2(n)+{\color{orange}{-23}}=−19$, so we added $$\color{orange}{23}$$ to both sides (the inverse operation)

15. anonymous

ohh ok

16. UnkleRhaukus

$\frac1{\color{blue}{-4}}\times\color{blue}{-4}\log_2 (n)=\frac1{\color{blue}{-4}}\times4$

17. UnkleRhaukus

which simplifies to . . . .

18. anonymous

log 2 n = -1

19. UnkleRhaukus

correct! now apply the definition of a log

20. anonymous

n = .5?

21. anonymous

i entered that and its says it wrong

22. anonymous

wait nvm

23. anonymous

ok, well thanks so much!

24. UnkleRhaukus

check solution by plugging them back into the original equation $−4\log_2(0.5)-23=-19\\−4\log_2(2^{-1})-23=-19\\ -4\times-1-23=-19\\ 4-23 = -19\\ -19=-19$ True!