Răspuns :
7+6×(x:4-18)=25
6×(x:4-18)=25-7
6×(x:4-18)=18
x:4-18=18:6
x:4-18=3
x:4=3+18
x:4=21
x=21×4
x=84
Probă
7+6×(84:4-18)=
=7+6×(21-18)=
=7+6×3=
=7+18=
=25 ( Adevarat )
6×(x:4-18)=25-7
6×(x:4-18)=18
x:4-18=18:6
x:4-18=3
x:4=3+18
x:4=21
x=21×4
x=84
Probă
7+6×(84:4-18)=
=7+6×(21-18)=
=7+6×3=
=7+18=
=25 ( Adevarat )