JAMB - Mathematics (1986 - No. 14)
Find n if log\(_{2}\) 4 + log\(_{2}\) 7 - log\(_{2}\) n = 1
10
14
27
28
Giải thích
log\(_2\) 4 + log\(_2\) 7 - log\(_2\) n = 1
= log\(_2\) (4 x 7) - log\(_2\) n = 1
\(\therefore\) log\(_2\) 28 - log\(_2\) n = 1
= \(\frac{28}{n} = 2^1\)
\(\frac{28}{n}\) = 2
2n = 28
∴ n = 14