If log102 = 0.3010 and log107 = 0.8451, then the value of

Given that , log₁₀2.8 = log₁₀( 4 × 0.7 )

∴ log	a	= log a - log b
	b

= log₁₀		2 × 2 ×	7
			10

= log₁₀2 + log₁₀2 + log₁₀7 – log₁₀10
= 0.3010 + 0.3010 + 0.8451 – 1 { ∴ log₁₀10 = 1 }
Hence , Log₁₀2.8 = 1.4471 – 1 = 0.4471