Răspuns:
a=9
Explicație pas cu pas:
100–[36+6×9–(a÷3+15)]÷3=76
[36+6×9–(a÷3+15)]÷3=100–76
[36+6×9–(a÷3+15)]÷3=24
[36+6×9–(a÷3+15)]=24×3
36+6×9–(a÷3+15)=72
54–(a÷3+15)=72-36
54–(a÷3+15)=36
(a÷3+15)=54–36
a÷3+15=18
a÷3=18-15
a÷3=3
a=3×3
