Răspuns :
[(2a-5):5]-6=5
2a=(5+5)x5-6
2a=10x5-6
2a=50-6
2a=44
a=44:2
a=22
2a=(5+5)x5-6
2a=10x5-6
2a=50-6
2a=44
a=44:2
a=22
(a*2-5):5=5+6
(a*2-5):5=11
a*2-5=5*11
a*2-5=55
a*2=55+5
a*2=60
a=60:2
a=30