WAEC - Mathematics (2003 - No. 29)
If \(\frac{3^{(1-n)}}{9^{-2n}}\) = \(\frac{1}{9}\) find n
\(-\frac{3}{2}\)
\(\frac{1}{3}\)
-1
-3
Εξήγηση
\(\frac{3^{(1-n)}}{9^{-2n}}\) =\(\frac{1}{9}\)
3\(^{1-n}\times 3^{-2(-2n)} = 3^{-2}\)
1 - n - 2(-2n) = -2
1 - n + 4n = -2
n = -1
3\(^{1-n}\times 3^{-2(-2n)} = 3^{-2}\)
1 - n - 2(-2n) = -2
1 - n + 4n = -2
n = -1