6.a+b=4 (a-b)
a-b=(a+b:4)
42=(a+b):4
a+b=42×4
a+b=168
a-b=42
2a=168+42
2a=210
a=210:2
a=105
a+b=168
105+b=168
b=168-105
b=63
7. |____|____|____|____|____|____|
1/4 1/3 3/4 15 inot
15×3=45 (sah )
(15+45):2=60:2=30 (volei )
30 fotbal
45+15+30+30=60+30=90+30=120 copii
