Răspuns :
143-(2a+22):2=57
(2a+22):2=143-57
(2a+22):2=86
2a+22=86x2
2a+22=172
2a=172-22
2a=150
a=150:2
a=75
(2a+22):2=143-57
(2a+22):2=86
2a+22=86x2
2a+22=172
2a=172-22
2a=150
a=150:2
a=75