7(0.3c - 5) - 2(c - 3(0.4c + 9)) = 7 * 0.3c - 7 * 5 - 2(c - 3 * 0.4c - 3 * 9) = 2.1c - 35 - 2(c - 1.2c - 27) = 2.1c - 35 - 2c + 2.4c + 54 = 2.1c - 2c + 2.4c + 54 - 35 = 2.5c + 19.
7(0.3c - 5) - 2(c - 3(0.4c + 9)) = 7 * 0.3c - 7 * 5 - 2(c - 3 * 0.4c - 3 * 9) = 2.1c - 35 - 2(c - 1.2c - 27) = 2.1c - 35 - 2c + 2.4c + 54 = 2.1c - 2c + 2.4c + 54 - 35 = 2.5c + 19.