1zad. dane: log21 7=m
Obliczyć: log7 27
oraz
2zad.dane: log5 2=m
obliczyć: log2 25
| log7 7 | 1 | |||
log21 7 = | = | = m | ||
| log7 21 | 1 + log7 3 |
| 1 | 1 − m | ||
= m ⇒ (1 + log7 3)m = 1 ⇒ log7 3 = | |||
| 1 + log7 3 | m |
| 3 − 3m | 3 | |||
log7 27 = log7 33 = 3 log7 3 = | = | − 3 | ||
| m | m |