Răspuns :
x-suma de bani pe care a avut-o Andrei la inceput
x+120-65+70-150+50=100
x= 100-50+150-70+65-120
x=50+150-70+65-120
x=200-70+65-120
x=130+65-120
x=195-120
x=75
x+120-65+70-150+50=100
x= 100-50+150-70+65-120
x=50+150-70+65-120
x=200-70+65-120
x=130+65-120
x=195-120
x=75
Notam suma de bani cu x.
[(x+120)-65+70]-150+50=100
[(x+120)-65+70]-150=50
(x+120)-65+70=200
(x+120)-65=130
x+120=195
x=75
[(x+120)-65+70]-150+50=100
[(x+120)-65+70]-150=50
(x+120)-65+70=200
(x+120)-65=130
x+120=195
x=75