Question

7log16/15+6log8/3+5log2/5+log32/25​

Answer 1

7( log 16 - log 15 ) + 6 ( log 8 - log 3 )+ 5 ( log 2 - log 5 ) +( log 32 - log 25)

= 7 {log 2⁴ - log ( 3×5) } + 6( log 2³- log 3)+ 5

( log2- log5) + (log 2 to the power of 5 -log 5²)

=7(4log2-log3-log5)+ 6 ( 3log2- log3)+

5(log2-log5) + 5log2-2log5

=28 log 2 - 7 log 3 - 7 log 5 + 18 log2 - 6 log 3

+ 5 log 2 - 5 log 5 + 5 log2 - 2log 5

= 28 log 2 + 18 log 2 +5 log 2 +5log2 - 7log3-

6 log 3 -7log 5 - 5 log 5- 2 log 5

= 56 log2 -13log3-14log5

= 56× 0.30103 - 13× 0.47712 - 14× 0.69897

= 16.85768 - 6.20256 - 9.78558

= 0.86954