Răspuns: a = 14
Explicație pas cu pas:
3 + 222 : 2 × 5 + [92 + 2 × 4 × (29 - a × 2 : 7 ) × 9 ] + 100 = 2 550
3 + 111 × 5 + [ 92 + 8 × ( 29 - a × 2 : 7 ) × 9 ] = 2 550 - 100
558 + [ 92 + 8 × ( 29 - a × 2 : 7 ) × 9 ] = 2 450
92 + 8 × ( 29 - a × 2 : 7 ) × 9 = 2 450 - 558
92 + 8 × ( 29 - a × 2 : 7 ) × 9 = 1 892
8 × ( 29 - a × 2 : 7 ) × 9 = 1 892 - 92
8 × ( 29 - a × 2 : 7 ) × 9 = 1 800
29 - a × 2 : 7 = 1 800 : 9 : 8 → aplic metoda mersului invers
29 - a × 2 : 7 = 200 : 8
29 - a × 2 : 7 = 25
a × 2 : 7 = 29 - 25
a × 2 = 4 × 7
a × 2 = 28
a = 28 : 2
a = 14
