Răspuns :
((x:5) · 2) :4 +5 = 9
((x:5) · 2 ): 4 = 4
(x:5) ·2 = 4·4
(x:5) ·2 = 16
x:5 = 16:2
x:5 = 8
x = 8·5
x = 40
((x:5) · 2 ): 4 = 4
(x:5) ·2 = 4·4
(x:5) ·2 = 16
x:5 = 16:2
x:5 = 8
x = 8·5
x = 40