diketahui log2=0,3010;log3=0,4771;log7=0,8451 tentukan: a).log 10,5=..? b)log 1/7=..?

[tex]log 10,5 = log \frac{21}{2} \\ = (log 3 + log 7) - log 2 \\ = (0,4771 + 0,8451) - 0,3010 \\ = 1,0212 \\ \\ log \frac{1}{7} = log 1 - log 7 \\ = 0 - 0,8451 \\ = - 0,8451[/tex]

a. log 10,5
= log 21/2
= log 21 - log 2
= log (3x7) - log 2
=log 3 + log 7 - log 2
=0,4771 + 0,8451 - 0,3010
=1,0212
b. log 1/7
=log 1- log 7
= 0 - 0,8451
= -0,8451