Tìm x biết x : 6 = 19

a, x : 6 = 19
b, 0 : x = 0
e, ( 8x - 16) (x - 5) = 0
c, x.3 + 7 = 16
d, ( x - 42) .3 = 51
f, x- 125 : 2 = 46