a) 841⋅675-841⋅575 = 841⋅(675-575) = 841 ⋅ 100 = 84100
б) 48 ⋅ 67 - 9450 : 21 + 69 = 3216 - 450 + 69 = 2835
в) $$6^2 + 2 = 6 \cdot 6 + 2 = 36 + 2 = 38$$
Ответ: a) 84100; б) 2835; в) 38