(10у + 2 * (7у - 2 )) : 5 = (5 * (4у + 3) +3у ) :5

(10у+14у-4):5 = (20у+15+3у):5
(10у+14у-4):5 - (20у+15+3у):5 = 0
(10у+14у-4-20у-15-3у):5 = 0
(у-19)/5=0
у=19