Răspuns :
(245:5+5•x):9+89=100
(245:5+5•x):9=100-89
(245:5+5•x):9=11
(245:5+5•x)=99
49+5x=99
5x=99-49
5x=50
x=10
(245:5+5•x):9=100-89
(245:5+5•x):9=11
(245:5+5•x)=99
49+5x=99
5x=99-49
5x=50
x=10