А) = - 36c - 3(25 - 60c + 36c^2) =
= - 36c - 75 + 180c - 108c^2 =
= 144c - 108с^2 - 75
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б) = 7b - 1 + 49b^2 - 7b - 4b + 3b^2 =
= 52b^2 - 4b - 1
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в) = 6k - 9 + 4k^ 2 - 6k - (9k^2 - 30k + 25) - 30k =
= - 9 + 4k^2 - 9k^2 + 30k - 25 - 30k =
= - 5k^2 - 34