sk|cz|

Mathematics

Quadratic Logarithmic Equations

1. Solve:

log(x + 24) + log(x -24) = 2       x > 24
Solution:
log(x + 24) + log(x -24) = 2
log( (x +24)(x – 24)) = log100
(x +24)(x -24)  =  100
x2 – 576  =  100
x2 – 676 = 0
(x – 26)(x + 26) = 0 => x1 = 26 v x2 = -26

K = {26}

2. Solve:

logkvadrat1zad
Solution:
logkvadrat1

3. Solve:

logkvadrat3zad
Solution:
logkvadrat3

4. Solve:

logkvadr4zad
Solution:
logkvadr4

5. Solve:

logkvadr5zad

Solution:

Substitution:
logkvadr5

6. Solve:

logkvadr6zad
Solution:
logkvadr6

7. Solve:

logkvadr7zad
Solution:
logkvadr7

8. Solve:

logkvadr8zad
Solution:
logkvadr8

9. Solve:

logkvadr9zad
Solution:
logkvadr9