Question

Nilai 7log343 - 3log1/81 + 2log0.25 adalah..

Answer 1

Aloga^b = b
aloga = 1
1/x^y = x^-y

7log343 = 7log7^3
= 3 × 7log7
= 3 × 1 = 3

3log1/81 = 3log1/(3^4)
= 3log3^-4
= -4 × 3log3
= -4 × 1 = -4

2log0,25 = 2log25/100
= 2log1/4
= 2log1/(2^2)
= 2log2^-2
= -2 × 2log2
= -2 × 1 = -2

7log343 - 3log1/81 + 2log0,25
= 3 - (-4) + (-2)
= 7 - 2 = 5