1 - a = (130 + 90) / 3001 - a = 220 / 3001 - a = 22 / 301 - a = 11 / 15
a = 1 - 11 / 15a = 15/15 - 11/15a = 4/15
Ответ: a = 4/15.
1 - a = (130 + 90) / 300
1 - a = 220 / 300
1 - a = 22 / 30
1 - a = 11 / 15
a = 1 - 11 / 15
a = 15/15 - 11/15
a = 4/15
Ответ: a = 4/15.