If 36: 81::X: 63, find the value of x.

If 36: x :: x :63, find the value of x.

If the middle term in the binomial expansion of (1/x+xsinx)^(10) is equal to (63)/8, find the value of x.

If x=3 and y=-1, find the values of each of the using identity: (9y^(2)-4x^(2))(81y^(4)+36x^(2)y^(2)+16x^(4))

If the middle term in the binomial expansion of ((1)/(x)+x sin x^(10)) is equal to (63)/(8), find the value of x.

If x=sqrt(81) , then find the value of (x^5+x^4)/(x^3)

If 4x= (81)/( x), then the value of x is :