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31 votes
31 votes
I need help with this math question

I need help with this math question-example-1
User Sounak
by
3.1k points

1 Answer

14 votes
14 votes

Answer:

B. 5

Explanation:

Step 1: Rewrite the equation a bit


(7^(3)/(4))/(7^(x)/(8))=\sqrt[8]{7}\\7^(3)/(4)^-^(x)/(8)=7^(1)/(8)

Step 2: Place a logarithm base 7 on both sides


7^(3)/(4)^-^(x)/(8)=7^(1)/(8)\\log_77^(3)/(4)^-^(x)/(8)=log_77^(1)/(8)\\((3)/(4)-(x)/(8))log_77=(1)/(8)log_77\\((3)/(4)-(x)/(8))1=(1)/(8)1\\(3)/(4)-(x)/(8)=(1)/(8)

Step 3: Solve for x


(3)/(4)-(x)/(8)=(1)/(8)\\(6)/(8)-(x)/(8)=(1)/(8)\\-(x)/(8)=-(5)/(8)\\(x)/(8)=(5)/(8)\\x=5

Neat exponent question :)

User Rajesh Wadhwa
by
2.9k points
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