1. log 3 =
0,477 dan log 2 = 0,301
Nilai log 18 = ….
a. 1,552
b. 1,525
c. 1,255
d. 1,235
e. 1,225
log 3 =
0,477 dan log 2 = 0,301
log 18 =
log 9 x 2
= log 9 + log 2
= log 32 + log 2
= 2 (0,477) + 0,301
= 0,954 + 0,301
= 1,255 (c)
2. log 2 =
0,301 dan log 5 = 0,699
Nilai log 5 + log 8 + log 25 = ….
a. 2
b. 3
c. 4
d. 5
e. 6
log 2 =
0,301 dan log 5 = 0,699
= log 5
+ log 8 + log 25
= log 5
+ log 23 + log 52
= log 5
+ 3.log 2 + 2.log 5
= 0,699
+ 3(0,301) + 2(0,699)
= 0,699
+ 0,903 + 1,398
= 3,0 (b)
3. Diketahui log 4,72 = 0,674
Nilai dari log 4.720 = ….
a. 1,674
b. 2,674
c. 3,674
d. 4,674
e. 5,674
log 4,72 = 0,674
log 4.720 = log (4,72 x 1000)
= log 4,72
+ log 1000
=
log 4,72 + log 103
= 0,674 + 3
= 3,674 (c)
4. Diketahui log 3 = 0,477 dan log 5 = 0,699. Nilai log 135 = ….
a. 2,778
b. 2,732
c. 2,176
d. 2,130
e. 2,260
log 3 = 0,477 dan log 5 = 0,699.
log 135 = log (27 x 5)
log 135 = log (27 x 5)
= log 27 + log 5
= log 33 + log 5
= 3(0,477) + 0,699
= 1,431 + 0,699
= 2,130 (d)
5. Diketahui log 3 = a dan log 2 = b. Maka log 18 = ….
a. 2a - b
b. 2a + b
c. a + 2b
d. a - 2b
e. a - b
Diketahui log 3 = a dan log 2 = b.
log 18 = log (9 x 2)
log 18 = log (9 x 2)
= log 9 + log 2
= log 32 + log 2
= 2.log 3 +
log b
= 2(a) + b
= 2a + b (b)
6. Diketahui plog 27 = 3x
Maka plog 243 = ….
a. 4x
b. 5x
c. 6x
d. 7x
e. 8x
plog 27 = 3x
33 = p3x
Maka: x = 1 dan p = 3
plog 243 = 3log (3)5
= 5.3log 3
= 5 . X
= 5x (b)
7. Diketahui log 2 = 0,301
Maka log 50 = ….
a. 0,699
b. 1,301
c. 1,699
d. 2,301
e. 2,699
log 2 = 0,301
log 50 = log (100 : 2)
= log 100 – log 2
= log 102 – log 2
= 2 – 0,301
= 1,699 (c)
8. Jika 2log x =
3. Tentukan nilai x = ….
a. 5
b. 6
c. 7
d. 8
e. 9
2log x = 3 --> x = 23
x = 8 (d)
9. Jika 4log 64 =
x. Tentukan nilai x = ….
a. 1
b. 2
c. 3
d. 4
e. 5
4log 64 = x --> 4x = 64
4x = 44
x = 4 (d)
10. Nilai dari 2log 8 + 3log 9 =
….
a. 1
b. 2
c. 3
d. 4
e. 5
= 2log 8 + 3log 9
= 2log 23 + 3log 32
= 3 + 2
= 5 (e)
