РЕШИ УРАВНЕНИЯ

300-y*5=210
(300-y)*5=210
(300-18)*y=1410
(150-20):y=65
5*y-600=900
(y+4)*7=350

300-y*5=210300 - 5у = 210300 - 210 = 5у5у = 90у = 90 : 5у = 18проверка:300 - 18 * 5 = 300 - 90 = 210210 = 210(300-y)*5=2101500 - 5у = 2101500 - 210 = 5у5у = 1290у = 1290 : 5у = 258проверка:(300 - 258) * 5 = 42 * 5 = 210210 = 210(300-18)*y=1410282у = 1410у = 1410 : 282у = 5проверка:(300 - 18) * 5 = 282 * 5 = 14101410 = 1410(150-20):y=65130 : у = 65у = 130 : 65у = 2проверка:(150 - 20) : 2= 130 : 2 = 6565 = 655*y-600=9005у = 900 + 6005у = 1500у = 1500 : 5у = 300проверка:5 * 300 - 600 = 1500 - 600 = 900900 = 900(y+4)*7=3507у + 28 = 3507у = 350 - 287у = 322у = 322 : 7у = 46проверка:(46 + 4 ) * 7 = 50 * 7 = 350350 = 350