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Mathematical Methods — Question 1

QCAA 2021, Paper 1 · 1 mark

Q1 · 2021 · Technology-freeSimple familiar1 mark

QUESTION 1

2\log_{10}(x)-\log_{10}(3x)

is equal to

(A)

{\log_{10}}\left(\frac{x}{3}\right)

(B)

\log_{10}(x^2-3x)

(C)

\dfrac{2\log_{10}(x)}{\log_{10}(3x)}

(D)

-\log_{10}(x)

ABCD

Question linkOriginal paper

WORKED SOLUTION

Answer A

1 mark

ANSWER

A

Worked solution

2\log_{10}x=\log_{10}(x^2)

, so

2\log_{10}x-\log_{10}(3x)=\log_{10}(x^2/(3x))=\log_{10}(x/3)

.

Selects option A.

[1 mark]

Worked explanation by QCE Vault; correct option verified against the QCAA answer key.

View the full QCAA marking guide

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