Given that $9^{\frac{1}{2}} = 27^{x} + 3^{1+x}$
find the exact value of x. - Edexcel - GCSE Maths - Question 20 - 2019 - Paper 1
Question 20
Given that $9^{\frac{1}{2}} = 27^{x} + 3^{1+x}$
find the exact value of x.
Worked Solution & Example Answer:Given that $9^{\frac{1}{2}} = 27^{x} + 3^{1+x}$
find the exact value of x. - Edexcel - GCSE Maths - Question 20 - 2019 - Paper 1
Step 1
Step 1: Convert to a Common Base
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Answer
We first express all terms using base 3. Recall that:
9=32
27=33
Thus, we can rewrite the equation:
(32)21=(33)x+31+x
This simplifies to:
31=33x+31+x
Step 2
Step 2: Set Exponents Equal
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Answer
Now, we factor out the common term from the right side:
31=31+x(1+32x−(1+x))
This means we have:
31=31+x
Equating the exponents gives:
1=1+x
Step 3
Step 3: Solve for x
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