Răspuns:
[(n + 4) • 4 - 4 ] : 4 = 4
(n + 4) • 4 - 4 = 4 • 4
(n + 4) • 4 - 4 = 16
(n + 4) • 4 = 16 + 4
(n + 4) • 4 = 20
n + 4 = 20 : 4
n + 4 = 5
n = 5 - 4
n = 1
2.
[ ( a × 2 ) × 2 - 5 × 5 ] × 18 = 3 438
( a × 2 ) × 2 - 25 = 3 438 : 18
( a × 2 ) × 2 - 25 = 191
( a × 2 ) × 2 = 191 + 25
a × 2 = 216 : 2
a × 2 = 108
a = 108 : 2
Explicație pas cu pas: