Explicație pas cu pas:
4.
a-b=300
400-100=300
b=c×6
12=2×6
c=d+14
15=1+14
d=e:6
2=3:6
e:60=19
e=19×60
e=1140
1140:60=90
5.
a×b=10
5×2=10
b=c:9
2=18:9
c=d:3
2=6:3
d+e=50
30+20=50
e×9=207
e= 207:9
e=23
23×9=207
