Вправи 301 - 401 » 338

Розв’яжи рівняння. 67 – х = 48 х = 67 – 48 х = 67 – 47 – 1 х = 19________ 67 – 19 = 48 67 – 20 + 1 = 48 48 = 48 45 + с = 90 с = 90 – 45 с = 90 – 40 – 5 с = 45_________ 45 + 45 = 90 45 + 5 + 40 = 90 90 = 90 b – 30 = 7 b = 7 + 30 b = 37____ 37 – 30 = 7 7 = 7