what should be added to twice the rational no.-7/3 to get 3/7 ? urgent!!!!!!

Let the number added be Y

2 x( -7/3) + y = 3/7

2 x (-7/3) + y = 3/7

-14/3 + y =3/7

y = 3/7 + 14/3

y = 9/21 + 98/21 (LCM=21)

y = 108/21

y = 36/7