Question

Log2base10=a, log3base10=b, then find log base 10 128 /15

Answer 1

Answer:

㏒2 base 10 = a

㏒ 3 base 10 = b

= ㏒ 128/15 base 10

= ㏒ 128 base 10 - ㏒ 15 base 10

= 6 ㏒ 2 base 10 - (㏒ 3 + ㏒5) base 10

= 6a - 0.69b (∵ log 5 base 10 = 0.69 )