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21N.1.AHL.TZ0.3

pestleMathematicsAAHLPaper 121N· sl-1-7-laws-of-exponents-and-logssource ↗

Solve the equation log3x=12log23+log34x3, where x>0.

Markscheme / solution

attempt to use change the base                (M1)

log3x=log322+log34x3

attempt to use the power rule                (M1)

log3x=log32+log34x3

attempt to use product or quotient rule for logs, lna+lnb=lnab                (M1)

log3x=log342x3


Note:
The M marks are for attempting to use the relevant log rule and may be applied in any order and at any time during the attempt seen.


x=42x3

x=32x6

x5=132                (A1)

x=12                A1

 

[5 marks]

Examiners’ report
[N/A]