9 - 0.2(8 + x) - 0.4(5x - 6) = 9 - 1.6 - 0.2x - 2x + 2.4 = -0.2x - 2x + 2.4 + 9 - 1.6 = -2.2x + 9.8;
При x = -10;
-2.2 * (-10) + 9.8 = -22 + 9.8 = -12.2.
9 - 0.2(8 + x) - 0.4(5x - 6) = 9 - 1.6 - 0.2x - 2x + 2.4 = -0.2x - 2x + 2.4 + 9 - 1.6 = -2.2x + 9.8;
При x = -10;
-2.2 * (-10) + 9.8 = -22 + 9.8 = -12.2.