Logarithmic Properties

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GRE Quantitative Reasoning › Logarithmic Properties

Questions 1 - 9
1

Rewrite the following expression as a single logarithm

Explanation

Recall a few properties of logarithms:

1.When adding logarithms of like base, we multiply the inside.

2.When subtracting logarithms of like base, we divide the inside.

3. When multiplying a logarithm by a number, we can raise the inside to that power.

So we begin with this:

I would start with 3 to simplify the first log.

Next, use rule 1 on the first two logs.

Then, use rule 2 to combine these two.

So our answer is 6.06.

2

Explanation

When combining logarithms into one log, we must remember that addition and multiplication are linked and subtraction and division are linked.

In this case we have multiplication and division - so we assume anything that is negative, must be placed in the bottom of the fraction.

3

Explanation

When rewriting an exponential function as a log, we must follow the model below:

A log is used to find an exponent. The above corresponds to the exponential form below:

4

Explanation

In order to rewrite a log, we must remember the pattern that they follow below:

In this question we have:

5

Express as a single logarithm.

Explanation

Step 1: Recall all logarithm rules:

Step 2: Rewrite the first term in the expression..

Step 3: Re-write the third term in the expression..

Step 4: Add up the positive terms...

Step 5: Subtract the answer the other term from the answer in Step 4.

6

Explanation

In order to expand this log, we must remember the log rules.

7

Explanation

8

Explanation

9

Rewrite the following expression as a single logarithm

Explanation

Recall a few properties of logarithms:

1.When adding logarithms of like base, we multiply the inside.

2.When subtracting logarithms of like base, we divide the inside.

3. When multiplying a logarithm by a number, we can raise the inside to that power.

So we begin with this:

I would start with 3 to simplify the first log.

Next, use rule 1 on the first two logs.

Then, use rule 2 to combine these two.

So our answer is 6.06.