4y = kx + 6
=> y = k/4x + 3/2
2x+3y=10
=> 3y  = - 2x + 10
=> y = -2/3 x + 10/3
Để 2 đt song song vsnhau=> k/4 = -2/3 => k = -8/3 
b)có cùng tung độ gốc 
=> 2x+3y = 10 => y = -2/3x + 10/3
3x = my + 6=> y = 3/mx - 6/m 
=> -2/3.0 + 10/3 = 3/m . 0 - 6/m 
=> 10/3  = -6/m
=> m = -6/5