7) 504:9=56 randuri de tei
125:5=25 randuri de plopi
504:9-19=
=56-19
=37 randuri de castani
56+25+37=
=81+37
=118 randuri in total
8) 550+550:5=
= 550+110
=660 sportivi in total
660:10=66 antrenori
660+66=726 persoane in total
9) M+A=536 lei
A=M+36
M+M+36=536
2M+36=536
2M=536-36
2M=500
M=500:2
M=250 lei are Maria
A=250+36
A=286 lei are Alin
250+286=536 lei in total
10) b+f=524 elevi
f=b+56
b+b+56=524
2b+56=524
2b=524-56
2b=486
b=486:2
b=234 baieti
f=234+56
f=290 fete
234+290=524 elevi in total