#((3x)/(4y))^3-:(81x^2y^-6)^-(1/4)#
#:.(3^3x^3)/(4^3y^3)-:(3^(-4/4)*x^(-2/4)*y^(6/4))#
#:.(3^3x^3)/(4^3y^3)-:(3^-1*x^(-1/2)*y^(3/2))#
#:.(3^3x^3)/(4^3y^3) xx 1/(3^-1*x^(-1/2)*y^(3/2))" "# (multiply by the reciprocal)
#:.(3^(3-(-1))*x^(3-(-1/2)))/(4^3*y^(3+3/2)#
#:.(3^4*(x^(7/2)))/(4^3*y^(9/2))#
#:.(3^4x^(7/2))/(4^3y^(9/2)#