Răspuns:
(a-100)-(80-2 × (1+7+4 × 2)) : 6 = 45
(a-100)-(80-2 × (1+7+8)) : 6 = 45
(a-100)-(80-2 × 16) : 6 = 45
(a-100)-(80-32) : 6 = 45
(a-100)-(48) : 6 = 45
(a-100)-48 : 6 = 45
(a-100)-8 = 45
a-100-8 = 45
a-108 = 45
a = 45 + 108
a = 153
Deci, valoarea lui a este 153.