Question

Log (w2+21) - log (10)

Answer 1

Answer:

$w =7\ or\ w =3$

Step-by-step explanation:

Given

The right question is:

$\log(w^2+ 21) = \log(10w)$

Required

Solve for w

$\log(w^2+ 21) = \log(10w)$

Cancel log on both sides

$w^2+ 21 = 10w$

Equate to 0

$w^2 - 10w+ 21 = 0$

Split

$w^2 - 3w - 7w+ 21 = 0$

Factorize

$w(w - 3) - 7(w-3) = 0$

Factor out w - 3

$(w - 7)(w-3) = 0$

Solve for w

$w - 7 = 0\ and\ w - 3 = 0$

$w =7\ or\ w =3$