Explicație pas cu pas:
(h:5-5)•9+186:6=400:10
(h:5-5)•9+186:6=40
(h:5-5)•9+186=40•6
(h:5-5)•9+186=240
(h:5-5)•9=240-186
(h:5-5)•9=54
(h:5-5)=54:9
(h:5-5)=6
h:5=6+5
h:5=11
h=11•5
h=55