1. diketahui log 2=0,3010, log3=0,4771, dan log7=0,8451,tentukan a. log 18 b. log 21 c. log 105 d. log 1/7

log 18=2(0,4771)+0,3010=1,2552
log 21=0,4771+0,8451=1,3222
log 105=0,4771+0,8451+log 5
log 1/7=-0,8451

a. log 18 = log 9 x 2 = log 9 + log 2= log 3x3 + log 2 = log 3 + log 3 + log 2 = 0,4771 + 0,4771 + 0,3010 = 1,2552

b. log 21 = log 7 x 3 = log 7 + log 3 = 0,8451 + 0,4771 = 1,3222