Question

Simplify expression: 3^{−(4a+1)} −3^{−(4a−1)} + 3^{−4a}

Answer 1

$3^{-(4a+1)}-3^{-(4a-1)} + 3^{-4a} =3^{-4a-1 }-3^{- 4a+1 } + 3^{-4a}=\\ \\=3^{ -4a }*3^{-1}-3^{ - 4a }*3^1 + 3^{-4a} =3^{-4a}(3^{-1}-3+1)=3^{ -4a }*(\frac{1}{3}-2)=\\ \\=3^{ -4a }*(-1\frac{2}{3})=3^{ -4a }*(-\frac{5}{3})=3^{ -4a }*(-5)*\frac{1}{3} =-5 *3^{ -4a }*3^{-1}=\\ \\ =-5 *3^{ -4a +(-1)}=-5 *3^{ -4a -1}$