Exercise | Wiskunde op Tilburg University

Determine all the values of

$x$ such that

$^{64}\!\log 49=^8\!\log x$ .

Antwoord 1 correct

Fout

Antwoord 2 optie

$x=15$ .

Antwoord 2 correct

Fout

Antwoord 3 optie

$x=-15$ .

Antwoord 3 correct

Fout

Antwoord 4 optie

$x=7$

Antwoord 4 correct

Correct

Antwoord 1 optie

None of the other answers is correct.

Antwoord 1 feedback

Wrong: The correct answer is among them.

Try again.

Antwoord 2 feedback

Wrong:

$\dfrac{^{8}\!\log 49}{^{8}\!\log 64}\neq ^{8}\!\log 15$ .

See Properties logarithmic functions.

Antwoord 3 feedback

Wrong:

$\dfrac{^{8}\!\log 49}{^{8}\!\log 64}\neq ^{8}\!\log (-15)$ .

See Properties logarithmic functions.

Antwoord 4 feedback

Correct:

$^{64}\!\log 49=\dfrac{^{8}\!\log 49}{^{8}\!\log 64}=\dfrac{^{8}\!\log 49}{2}=^{8}\!\log 7$ . Hence,

$x=7$ .

Go on.