(7.7 - 0.2 × 8) ÷ 2
= (7.7 - 1.6) ÷ 2
= 6.1 ÷ 2
= 3.05元
答：每个文具盒3.05元.
方程：设每个文具盒x元.
2x + 8 × 0.2 = 7.7
2x = 7.7 - 1.6
2x = 6.1
x = 6.1 ÷ 2
x = 3.05
答：每个文具盒3.05元.