Express $8^{2x+3}$ in the form $2^y$, stating $y$ in terms of $x$. - Edexcel - A-Level Maths Pure - Question 5 - 2013 - Paper 3
Question 5
Express $8^{2x+3}$ in the form $2^y$, stating $y$ in terms of $x$.
Worked Solution & Example Answer:Express $8^{2x+3}$ in the form $2^y$, stating $y$ in terms of $x$. - Edexcel - A-Level Maths Pure - Question 5 - 2013 - Paper 3
Step 1
Step 1: Express 8 in terms of 2
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Answer
We know that 8 can be expressed as a power of 2: 8=23. Therefore, we can rewrite the expression as:
82x+3=(23)2x+3
Step 2
Step 2: Apply the Power of a Power Rule
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Answer
Using the power of a power rule, which states that (am)n=am⋅n, we can rewrite the expression as:
(23)2x+3=23(2x+3)=26x+9
Step 3
Step 3: State y in terms of x
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Answer
From the expression 26x+9, we can identify that in the form of 2y, we have: