X = 240 / 80 = 3
280 - a = 190 => a = 280 - 190 = 90
291 + a = 652 => a = 652 - 291 = 361
70 X = 490 => 70 7 = 490 => X = 7
X = 240 / 80 = 3
280 - a = 190 => a = 280 - 190 = 90
291 + a = 652 => a = 652 - 291 = 361
70 X = 490 => 70 7 = 490 => X = 7