$\sqrt[4]{81}\backslash sqrt[4]\{81\}$ = ……

$[(3^2{)}^3{]}^4[(3^2)^3]^4$ = ……

$2^4\times (32{)}^{-1}2^4\backslash times(32)^\{-1\}$ = ……

Base in $2x^{-3}2x^\{-3\}$ is …

$(125{)}^{-2\mathrm{/}3}(125)^\{-2/3\}$ = ……

$(\frac{25}{49}{)}^{\frac{1}{2}}(\backslash frac\{25\}\{49\})^\backslash frac\{1\}\{2\}$ = ……

${\displaystyle \frac{2^{a+3}\times 3^{2a+b}\times 6^{b+1}}{3^{a+b}\times 6^{a+b}}}\backslash cfrac\{2^\{a+3\}\backslash times3^\{2a+b\}\backslash times6^\{b+1\}\}\{3^\{a+b\}\backslash times6^\{a+b\}\}$ = ……

$(a^{-1}+b^{-1})(a^\{-1\}+b^\{-1\})$ ab = ……

$(a^0{)}^0(a^0)^0$ = ……

$9^x+9^{x-1}9^x+9^\{x-1\}$ = 90 then x = ……