Explore Westonci.ca, the premier Q&A site that helps you find precise answers to your questions, no matter the topic. Experience the convenience of finding accurate answers to your questions from knowledgeable professionals on our platform. Explore comprehensive solutions to your questions from a wide range of professionals on our user-friendly platform.

For what value of [tex]\( a \)[/tex] does [tex]\( 9=\left(\frac{1}{27}\right)^{2a+3} \)[/tex]?

A. [tex]\( -\frac{11}{3} \)[/tex]
B. [tex]\( -\frac{7}{3} \)[/tex]
C. [tex]\( \frac{7}{3} \)[/tex]
D. [tex]\( \frac{11}{3} \)[/tex]


Sagot :

To find the value of [tex]\( a \)[/tex] that satisfies the equation [tex]\( 9 = \left(\frac{1}{27}\right)^{2 + 3a} \)[/tex], we need to examine each given option for [tex]\( a \)[/tex]. Let's go through each option and check if it holds true for the equation.

### Evaluate for each option:

#### Option 1: [tex]\( a = -\frac{11}{3} \)[/tex]
[tex]\[ 2 + 3a = 2 + 3 \left(-\frac{11}{3}\right) = 2 - 11 = -9 \][/tex]
Now substituting this back in the equation:
[tex]\[ \left(\frac{1}{27}\right)^{-9} = 27^9 \][/tex]
We need to check if [tex]\( 27^9 = 9 \)[/tex]. Clearly, [tex]\( 27^9 \)[/tex] is not equal to 9, so this option is incorrect.

#### Option 2: [tex]\( a = -\frac{7}{3} \)[/tex]
[tex]\[ 2 + 3a = 2 + 3 \left(-\frac{7}{3}\right) = 2 - 7 = -5 \][/tex]
Now substituting this back in the equation:
[tex]\[ \left(\frac{1}{27}\right)^{-5} = 27^5 \][/tex]
We need to check if [tex]\( 27^5 = 9 \)[/tex]. Clearly, [tex]\( 27^5 \)[/tex] is not equal to 9, so this option is incorrect.

#### Option 3: [tex]\( a = \frac{7}{3} \)[/tex]
[tex]\[ 2 + 3a = 2 + 3 \left(\frac{7}{3}\right) = 2 + 7 = 9 \][/tex]
Now substituting this back in the equation:
[tex]\[ \left(\frac{1}{27}\right)^9 = \frac{1}{27^9} \][/tex]
We need to check if [tex]\( \frac{1}{27^9} = 9 \)[/tex]. Clearly, [tex]\( \frac{1}{27^9} \)[/tex] is not equal to 9, so this option is incorrect.

#### Option 4: [tex]\( a = \frac{11}{3} \)[/tex]
[tex]\[ 2 + 3a = 2 + 3 \left(\frac{11}{3}\right) = 2 + 11 = 13 \][/tex]
Now substituting this back in the equation:
[tex]\[ \left(\frac{1}{27}\right)^{13} = \frac{1}{27^{13}} \][/tex]
We need to check if [tex]\( \frac{1}{27^{13}} = 9 \)[/tex]. Clearly, [tex]\( \frac{1}{27^{13}} \)[/tex] is not equal to 9, so this option is incorrect.

### Conclusion:
None of the provided values for [tex]\( a \)[/tex] satisfy the equation [tex]\( 9 = \left(\frac{1}{27}\right)^{2 + 3a} \)[/tex]. As per the detailed checks, there is no correct value for [tex]\( a \)[/tex] among the given choices.