Solve for X : Log (X2 - 21) = 2 - Mathematics

Solve for x : log (x² - 21) = 2.

बेरीज

log ( x² - 21 ) = 2
⇒ log ( x² - 21) = log 100
⇒ x² - 21 - 100 = 0
⇒ x² - 121 = 0
⇒ x² = 121
⇒ x = `+- sqrt121`
⇒ x =`+-`11

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Laws of Logarithm

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पाठ 8: Logarithms - Exercise 8 (B) [पृष्ठ १०६]

पाठ 8 Logarithms
Exercise 8 (B) | Q 7.2 | पृष्ठ १०६

Express the following in a form free from logarithm:
a log x - b log y = 2 log 3

Evaluate the following without using tables :
log 5 + log 8 - 2 log 2

Solve for x : log (x + 5) + log (x - 5) = 4 log 2 + 2 log 3

Solve for x : ` ( log 128) / ( log 32 ) ` = x

Solve for x :
`log 225/log15` = log x

Solve for x : ` (log 64)/(log 8)` = log x

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State, true or false : log 1 x log 1000 = 0

State, true or false :
`log x/log y` = log x - log y

If log₁₀ 8 = 0.90; find the value of : log₁₀ 4