1. Jika 2log x = 3
Tentukan nilai x = ….
Jawab:
2log x = 3 à x = 23
x = 8.
2. Jika 4log 64 = x
Tentukan nilai x = ….
Jawab:
4log 64 = x à 4x = 64
4x = 44
x = 4.
3. Nilai dari 2log 8 + 3log 9 = ….
Jawab:
= 2log 8 + 3log 9
= 2log 23 + 3log 32
= 3 + 2
= 5
4. Nilai dari 2log (8 x 16) = ….
Jawab:
= 2log 8 + 2log 16
= 2log 23 + 2log 24
= 3 + 4
= 7
5. Nilai dari 3log (81 : 27) = ….
Jawab:
= 3log 81 – 3log 27
= 3log 34 – 3log 33
= 4 – 3
= 1
6. Nilai dari 2log 84 = ….
Jawab:
= 2log 84
= 4 x 2log 23
= 4 x 3
= 12
7. Nilai dari 2log Ö84 = ….
Jawab:
= 2log Ö84 à
= 2 x 2log 23
= 2 x 3
= 6
8. Jika log 100 = x
Tentukan nilai x = ….
Jawab:
log 100 = x à 10x = 100
10x = 102
x = 2.
9. log 3 = 0,477 dan log 2 = 0,301
Nilai log 18 = ….
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
10. log 2 = 0,301 dan log 5 = 0,699
Nilai log 5 + log 8 + log 25 = ….
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