diketahui 3log4=a dan 7log3=b nyatakan 28log108 dalam a dan b

28log108

(4×7)log(4×3×3×3)

(log4 + log3^3)/(log4+log7)

masukkan indeks 3

(3log4 + 3log3^3)/(3log4+3log7)

(a+3)/a+(1/b)

sederhanakan

(a+3)b/(ab+1)

Dik: 3log4= a; 7log3= b
Dit: 28log108= ?
Jwb:
28log108
= log108/log28
= log(4×27) / log(4×7)
= log4+log27 / log4+log7
= (3log4 + 3× 3log3) / (2× 3log4 + 3log7)
= (a+3) / (2a + 1/b)
= (a+3) / [(2ab+b)/b]
= b(a+3) / b(2a+1)
= a+3 / 2a+1

Maaf klo salah, trims :)