Răspuns:
42-{3×[19-2×(13-36:a)]-10}=1
3×[19-2×(13-36:a)]-10=42-1
3×[19-2×(13-36:a)]-10=41
3×[19-2×(13-36:a)]=41+10
3×[19-2×(13-36:a)]=51
19-2×(13-36:a)=51:3
19-2×(13-36:a)=17
2×(13-36:a)=19-17
2×(13-36:a)=2
13-36:a=2:2
13-36:a=1
36:a=13-1
36:a=12
a=36:12
a=3
