Question

Which of the following is the solution to the equation 25(z + 4) = 125 ?

Answer 1

its 25^(z+4)=125 sorry

Answer 2

Of which following?

To solve this equation, with one variable, you have to isolate the variable and the known numbers...

So what would be the 1st step to isolate z (and leave it on the left side of "=") ?
Hint: Think of isolating "z+4"

Answer 3

subtract 4

Answer 4

from both sides

Answer 5

z=-2.5 z=-0.5 z=3.5 z=5.5 are the answer choices

Answer 6

Sorry, just saw, your correction for the equation..

So to isolate z you have to change it from being the exponent (z+4)...
So what can you do that would "undo" the exponent?

Answer 7

oh ok. change signs?

Answer 8

No, not signs.

What is the "brother" of the exponent function?

Answer 9

PARENTHESIS

Answer 10

It's the logarithm! Now, can you find out the possible solution?

Answer 11

no thats why i came here i need help

Answer 12

Ok, I am trying to help you. Well, given this
\[\log_{2} 2 = ? \], what would be the result?

Answer 13

-2.5

Answer 14

How did you find this?

Do notice that the base and the variable inside the logarithmic function are the same.

Answer 15

ok im not sure

Answer 16

what is a lagarithmic function?

Answer 17

logarithmic*

Answer 18

Here, read this: http://en.wikipedia.org/wiki/Logarithm

When the base and the variable inside the logarithmic function are the same the result equals to 1.

So \[\log_{2} 2 = 1\] and \[\log_{25} 25 = 1\]

Also read this: http://en.wikipedia.org/wiki/List_of_logarithmic_identities , the "Canceling exponentials" sector.

Answer 19

ok