9^(3-x) = 81^(4-2x) => 9^(3-x) = 9^(8-4x) => 3-x = 8-4x => 3x = 5 => x=5/3
5/3 is the answer
9 ^( 3-x) =81^( 4-2x) (3^2)^(3-x)=(3^4)^(4-2x) 3^(2*(3-x))=3^( 4*(4-2x)) on camparing 2(3-x) =4(4-2x) 6-2x=16-8x -2x+8x=16-6 6x=10 x=10/6 x=5/3
x, y, z and k are four non zero positive integers satisfying 1/x + y/2 = z/3 + 4/k, minimum integral value of k for integral value of x, y and z will be