Question

TOLONG DI JAWAB ! 1. )jika log 3 =0,4771 dan log 5= 0,6990,maka log 45 adalah. . .
a.0,255 b.0,633 c.0,677 d.1,176 e.1,656

2) jika log 2=3010 dan log 3 = 0,4771, maka log 150 adalah ....
a.2,77781 b,2,761 c.1,8289 d.0,7781 e.0,1761

Answer 1

1) log 45 = log (3x3x5) = log 3 + log 3 + log 5 = 0,4771 + 0, 4771 + 0,6990 = 1,6532
2) log 150 = log (3x5x10) = log 3 + log (10/2) + log 10 = log 3 + log 10 - log 2 + log 10 = 0,4771 + 1 - 0,3010 +1 = 2,1761

Answer 2

log 45 = log ( 3² x 5)
          = log 3² + log 5
          = 2 . log 3 + log 5
          = 2 . 0 ,4771 + 0,6990
          = 0,9542 + 0,9960
          = 1,9502
log 150 = log (100 : 2 x 3)
            = log 100 - log 2 + log 3
            = 2 - 0,3010 + 0,4771
            = 2,1761