1-1 1/2у+3 2/5у=1 1/3у-2 7/15у+2 1/2

1 - 3/2у + 17/5у = 4/3у - 37/15у + 5/2

-3/2у + 17/5у - 4/3у + 37/15у = 5/2 - 1

-45/30у + 102/30у - 40/30у + 74/30у = 3/2

91/30у = 3/2

у = 3/2 : 91/30

у = 3/2 * 30/91

у = 90/182 = 45/91