0,6а - 2 = 0,7b
0,5b - 10 = 1/3а
Решение
0,5b = ( 1/3)a + 10
b = (2/3)a + 20
0,6a - 2 = 0,7b
6a - 20 = 7b
b = ( 6/7a ) - ( 20/7 )
( 2/3)a + 20 = ( 6/7)a - ( 20/7 )
14a + 20•21 = 18a - 60
18a - 14a = 420 + 60
4a = 480
a = 120
b = (6/7)•120 - ( 20/7 ) = ( 720 - 20 )/7 = 100
Ответ а = 120 ; b = 100