Question

Jika diketahui log3=0,4771 dan log5=0,6990 tentukan
a. log45
b . log0,36
c . log5/3
d . log√135

jika diketahui log5=x log7=y tentukan x dan y
a . log 175
b . log 3,5

Answer 1

A.log45 =log3pangkat3+log5
=(0,4771)pangkat3+(0,6990)
Pake kalkulator
Jadi 45nya uraikan

Answer 2

A. log 45 = log (9.5) = log (3³.5) = log 3³ + log 5 = 3 log 3 + log 5 = 3(0,4771) + 0,6990 = 2,1303
b. log 0,36 = log (9/25) = log (3³/5⁵) = log 3³ - log 5⁵ = 3 log 3 - 5 log 5 = 3(0,4771) - 5(0,6990) = -2,0637
c. log 5/3 = log 5 - log 3 = 0,6990 - 0,4771 = 0,2219
d. log √135 = log(3(3.5)¹/²) = log 3 + log 3¹/² + log 5¹/² = log 3 + 1/2 log 3 + 1/2 log 5 = 0,4771 + 1/2(0,4771) + 1/2(0,6990) = 2,06515

--------------------------------------------------------------------------------------------------------------
a. log 175 = log (5².7) = log 5² + log 7 = 2 log 5 + log 7 = 2x + y
b. log 3,5 = log 5.7/10 = log 5 + log 7 - log 10 = x + y - 1