Question

Diketahui 2log9 = a, 5log2 = b, 5log7 = c . Tentukan nilai 3log16 - 14log25 / 5log63 dalam bentuk a, b, c

Answer 1

3log16=3log2^4
=4. 3log2
=4.1/4log3
=4.a
=2a

14 log25=14log5^2
=5log14=3log2+5log7
=14log5=1/b+c

5 log63=5log(2.3.7)
=5log2+5log3+5log7
=b+c+c
=b+2c

5log63=5log(6.7)
=5log(2.3.7)
=5log2=b
5log3=5log7/5log5
=c/1
=c
5log7=c

3log16-14log25/5log63
=2a-1/b+c /b+2c