Х-290=470+230 x+320=90•8
X-290=470+230 x=470+230+290 x=700+290 x=990 x+320=90·8 x=720-320 x=400
1) x - 290 = 470 + 230 x - 290 = 700 x = 700 + 290 x = 990 проверка: 990 - 290 = 470 + 230 700 = 700 2) x + 320 = 90 * 8 x + 320 = 720 x = 720 - 320 х = 400 проверка: 400 + 320 = 90 * 8 720 = 720