Find the exact value of $x$ for which
$$ ext{log}_2(2x) = ext{log}_2(5x + 4) - 3$$
Given that
$$ ext{log}_b(y) + 3 ext{log}_2(2) = 5$$
express $y$ in terms of $a$ - Edexcel - A-Level Maths Pure - Question 8 - 2013 - Paper 4
Question 8
Find the exact value of $x$ for which
$$ ext{log}_2(2x) = ext{log}_2(5x + 4) - 3$$
Given that
$$ ext{log}_b(y) + 3 ext{log}_2(2) = 5$$
express $y$ in terms of $... show full transcript
Worked Solution & Example Answer:Find the exact value of $x$ for which
$$ ext{log}_2(2x) = ext{log}_2(5x + 4) - 3$$
Given that
$$ ext{log}_b(y) + 3 ext{log}_2(2) = 5$$
express $y$ in terms of $a$ - Edexcel - A-Level Maths Pure - Question 8 - 2013 - Paper 4
Step 1
Find the exact value of $x$ for which log_2(2x) = log_2(5x + 4) - 3
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Answer
To solve for x, start by isolating the logarithmic terms:
Rewrite the equation:
extlog2(2x)+3=extlog2(5x+4)
Use the property of logarithms that allows you to combine them:
extlog2(2x)+extlog2(8)=extlog2(5x+4)
Apply the addition property of logarithms:
extlog2(16x)=extlog2(5x+4)
Set the arguments equal to each other:
16x=5x+4
Rearrange to solve for x:
16x−5x=411x=4x = rac{4}{11}
Step 2
Given that log_b(y) + 3log_2(2) = 5 express y in terms of a
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Answer
Start by isolating y:
Rewrite the equation using properties of logarithms:
extlogb(y)=5−3extlog2(2)