Tìm x; a) 2/9 : x = 2/3; b) x : 4/5 = 5/2; c) 4/5 : x = 1/2

Tìm x:
a) 2/9 : x = 2/3
b) x : 4/5 = 5/2
c) 4/5 : x = 1/2
            x = 4/5 x 1/2  8/5
            x =