Răspuns :
b = nr de banci
4b +6 = 5(b-6)
4b+6 = 5b - 30
30+6 = 5b - 4b
b = 36 banci
4 · 36 +6 = 150 elevi
4b +6 = 5(b-6)
4b+6 = 5b - 30
30+6 = 5b - 4b
b = 36 banci
4 · 36 +6 = 150 elevi