5+5÷{[5+5×(a-5)]÷5-5}-5÷5=25÷5
5+5÷{[5+5×(a-5)]÷5-5}-1=5
5+5÷{[5+5×(a-5)]÷5-5}=5+1
5+5÷{[5+5×(a-5)]÷5-5}=6
5÷{[5+5×(a-5)]÷5-5}=6-5
5÷{[5+5×(a-5)]÷5-5}=1
[5+5×(a-5)]÷5-5=5:1
[5+5×(a-5)]÷5-5=5
[5+5×(a-5)]÷5=5+5
[5+5×(a-5)]÷5=10
5+5×(a-5)=10×5
5+5×(a-5)=50
5×(a-5)=50-5
5×(a-5)=45
a-5=45:5
a-5=9
a=9+5
a=14
PROBA
5+5÷{[5+5×(14-5)]÷5-5}-5÷5=25÷5
5+5:[(5+5×9):5-5]-1=5
5+5:[(5+45):5-5]-1=
=5+5:(50:5-5)-1=
=5+5:(10-5)-1=
=5+5:5-1=
=5+1-1=
=5+0=
=5 (adevărat a dat 5)
