Saturday, 29 April 2017

LOGARITHMS 20


If logx 2401 – log3729 = -4; find x

solution

logx 2401 – log3729 = -2

logx 2401 – log336 = -2

logx 2401 – 6log33 = -2

logx 2401 – 6 x 1 = -2

logx 2401 – 6 = -2

logx 2401 = -2 + 6

logx 2401 = 4 

2401 = x4        2401=7x7x7x7=74 by prime factors

74 = x4      Powers cancel out

x = 7


Hence x = 7.

TRY THIS………….


If logm2048 – log6216 = 8; find m

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