Răspuns :
100-[(b:2+5)+2xb]=5
(b:2+5)+2b=100-5
(b:2+5)+2b=95
b:2+5=95-2b
b:2=95-2b-5
b:2=90-2b
b=(90-2b)x2
b=180-4b
180=4b+b
180=5b
b=180:5
b=36
(b:2+5)+2b=100-5
(b:2+5)+2b=95
b:2+5=95-2b
b:2=95-2b-5
b:2=90-2b
b=(90-2b)x2
b=180-4b
180=4b+b
180=5b
b=180:5
b=36