Question

va rog ajutati ma la problemele 11,12 şi 13

Answer 1

11.
a+b+c=216
a=3(b+c) =3b+3c=3b+3(b+20)=3b+3b+60=6b+60    
c=b+20
6b+60+b+b+20=216
8b=216-80
8b=136
b=17 timbre
c=17+20=37 timbre
a=3(17+37)=162 timbre

12.
a=bile albe
b=5a=bile rosii
c=a+b=a+5a=6abile negre
a+b+c=624
a+5a+6a=624
12a=624
a=52 bile albe
b=5×52=260 bile rosii
c=52+260=312 bile negre

13.
a=muncitori schimb dimineata
b=muncitori schimb dupa masa
c=muncitori schimb noapte
a=b+400=2c+400
b=2c
2c+400+2c+c=1200
5c=800
c=160 muncitori schimb noapte
b=2c=2×160=320 muncitori schimb dupa masa
a=b+400=320+400=720 muncitori schimb dimineata