Răspuns :
(9+9x9):9+9+9:9=
=(9+81):9+9+9:9=
=90:9+9+9:9
=10+9+9:9=
=10+9+1
=19+1=
=20
(9+9x9):9+9+9:9 = (9+81):9+9+1 = 90:9+9+1 = 10+9+1 = 19+1 = 20
(9+9x9):9+9+9:9=
=(9+81):9+9+9:9=
=90:9+9+9:9
=10+9+9:9=
=10+9+1
=19+1=
=20