Răspuns :
[5*(5x-5)-120]*5-25=125
[5*(5x-5)-120]*5=125+25
[5*(5x-5)-120]*5=150
5*(5x-5)-120=150:5
5*(5x-5)-120=30
5*(5x-5)=120+30
5*(5x-5)=150
5x-5=150:5
5x-5=30
5x=30+5
5x=35
x=35:5
x=7
Răspuns:
[5×(5×5)-120]×5-25=
(5×25-120)×5-25=
(125-120)×5-25=
5×5-25=
25-25=0