(6у+14):2+15=40, (6у+14):2=40-15, (6у+14):2=25, 6у+14=25*2, 6у+14=50, 6у=50-14, 6у=36, у=36:6, у=6.
42к-28к+180=600, 14к=600-180, 14к=420, к=420:14, к=30
(6у+14)/2+15=40
(6у+14)/2=40-15
6у/2+14/2=25
3у+7=25
3у=25-7
3у=18
у=18/3
у=6
42к-28к+180=600
14к=600-180
14к=420
к=420/14
к=30
(6у+14):2+15=40, (6у+14):2=40-15, (6у+14):2=25, 6у+14=25*2, 6у+14=50, 6у=50-14, 6у=36, у=36:6, у=6.
42к-28к+180=600, 14к=600-180, 14к=420, к=420:14, к=30
(6у+14)/2+15=40
(6у+14)/2=40-15
6у/2+14/2=25
3у+7=25
3у=25-7
3у=18
у=18/3
у=6
42к-28к+180=600
14к=600-180
14к=420
к=420/14
к=30