26+(6×h-7×3 ):9=27
26+(6×h-21):9=27
(6×h-21 ):9=27-26
(6×h-21 ):9=1
(6×h-21 ) = 1×9
(6×h-21 )= 9
6×h=9+21
6×h=30
h=30:6
h=5
verificare :
26+(6×5-7×3):9=
26+(30-21):9=
26+9:9=
26+1=27