Solve log3 27 – x = 5 Solve log3 27 – x = 5 @Mathematics

Question

anonymous · Answer

what number do you raise 3 to, inorder to get 27?

anonymous · Answer

the base is 3, thats how the problem is

anonymous · Answer

right i understand, but 3^(what???)=27

anonymous · Answer

Ohhh! that would be 5

anonymous · Answer

no, it would not

anonymous · Answer

yes but that says what power to you raise (3) to to get (27) then you solve from there to get your x

anonymous · Answer

Ok it would be 3

anonymous · Answer

very nice

anonymous · Answer

now, simple solve the equation

anonymous · Answer

yes so 3-x=5

anonymous · Answer

Yeah but dont you have to use the power product property for this?

anonymous · Answer

no, just solve : 3-x=5

lilg132 · Answer

3 - x = 5

x = 5 - 3

x = 2

anonymous · Answer

Ok, so can you put this step by step?

anonymous · Answer

why cant you do?

lilg132 · Answer

did you understand how to work out the log3 27?

anonymous · Answer

Yeah but what happens to the 5?

anonymous · Answer

what? havent you been paying attention

anonymous · Answer

Yess I have, but Im still a bit confused.

lilg132 · Answer

ok once you solve the log3 27 the answer to that is 3

so you replace log3 27 with 3 in the equation and you will get

3 - x = 5

now you have to rearrange the equation to get x

so you bring 3 to the other side so your only left with x

x = 5 - 3

x = 2

anonymous · Answer

ok so $$\log_{3}(27)-x=5 $$
so what power do you rasise 3 to to get 27? 3 so now you have
3-x=5 solve for x
-x=2
x=-2

lilg132 · Answer

damn your right :p i totally missed out the minus x 

so the answer is 

-x = 2

x = -2

lilg132 · Answer

do you still not understand mitosuki?

anonymous · Answer

I checked the answer but when I plug in the -2 it doesnt work

anonymous · Answer

It is -216.

anonymous · Answer

Yeah cause you put it this way: 3^5 = 27 -x

anonymous · Answer

did you plug $$\log_{3}(27)  $$ in as (log(27)/log(3)) because you calculator can only do log in base 10 so you have to use log base change formula

anonymous · Answer

so to plug it into a calculator it should look like this ((log(27)/log(3))-5
which equals -2

anonymous · Answer

Yeah but why -5?

anonymous · Answer

well look at your starting equation and i jsut solved for x first so i could plug it into my calculator

anonymous · Answer

Ok, thank you I understand it now :)

anonymous · Answer

yep glad i could help