Уравнения (720-t•6): 9=60 и 4•(250: a+12)=68

(720-t*6):9=60
720-t*6=60*9
720-t*6=540
t*6=720-540
t*6=180
t=180:6
t=30
(720-30*6):9=60
60=60

(720-t*6):9=60
720-t*6=60*9
720-t*6=540
t*6=720-540
t*6=180
t=180:6
t=30

(720-30*60):9=60
(720-180):9=60
540:9=60
60=60

4*(250:a+12)=68
250:a+12=68:4
250:a+12=17
250:a=17-12
250:a=5
a=250:5
a=50

4*(250:50+12)=68
4*(5+12)=68
4*17=68
68=68