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Which equation has x=-6 as the solution? A-logx36=2. B-log3(2x-9)=3. C-log3 216=x. D-log3(-2x-3)=2

User TornadoAli
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2 Answers

3 votes

Answer:

it's D

Explanation:

insert it into all of the equations until you get to like x=x and not x=some other number

with d, 9=9 so thats the answer

thank you for coming to my ted talk

User Mattrick
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4 votes
Posted to your other question as well:

So we have:

A)
\log_x(36)=2

B)
\log_3(2x-9)=3

C)
\log_3(216)=x

D)
\log_3(-2x-3)=2

We need to try x = –6 in each equation until we find a solution that makes both sides of the equation equal.

For A, this gives an undefined result. Logarithms are only defined for bases that are positive real numbers not equal to 1.

For B, this again gives an undefined result. The logarithm of a number is only defined when that number is a positive real number. It would be –21, which is undefined.

For C, we have a defined operation, but
\log_3(216)=4.893 \\eq -6.

Finally, for D, we have


\log_3(-2(-6)-3)=2\\ \log_3(9)=2 \\ 3^2=9 \\ 9=9

This is true.
User Kipzes
by
8.3k points

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