WAEC - Further Mathematics (2023 - No. 6)
If\((\frac{1}{9})^{2x-1} = (\frac{1}{81})^{2-3x}\)find the value of x
\(-\frac{5}{8}\)
\(-\frac{3}{4}\)
\(\frac{3}{4}\)
\(-\frac{5}{8}\)
คำอธิบาย
\((\frac{1}{9})^{2x-1} = (\frac{1}{81})^{2-3x}\)
\((\frac{1}{9})^{2x-1} = (\frac{1}{9})^{2(2-3x)}\)
\((\frac{1}{9})^{2x-1} = (\frac{1}{9})^{4-6x}\)
Since the bases are equal, powers can be equated
= 2x - 1 = 4 - 6x
= 2x + 6x = 4 + 1
= 8x = 5
\(\therefore x = \frac{5}{8}\)