Tolong nomor 27 dan 28
Jawab:
27) B. -24
28) C. 12
Penjelasan dengan langkah-langkah:
27) 2log 125 x 5log 9 x 3log 1/16
= (2log 5^3) x (5log 3^2) x (3log 2^-4)
= (3 x 2log 5) x (2 x 5log 3) x (-4 x 3log 2)
= (3 x 2 x -4) x (2log 5 x 5log 3 x 3log 2)
= (-24) x (2log 2)
= -24 x 1 = -24
28) (2log 81 x 3log 16) – (5log 49 x 7log 25)
= (2log 3^4) x 3log 2^4) – (5log 7^2 x 7log 5^2)
= (4 x 2log 3) x 4 x 3log 2)) – (2 x 5log 7) x 2 x 7log 5))
= (4 x 4) x (2log 3 x 3 log 2)) – (2 x 2) x 5log 7 x 7 log 5))
= (16) x (2log 2)) – (4) – 5log 5))
= (16×1) – (4×1) = 16-4 = 12