1)
4) (8d - 2y) * (-0,6) при x= 5
(8d-5)х(-0,6) = 3d (-0,6х)
3*5 (-0.6х) = 15 * (-0,6х) = -9х
5)0,9(-8 - 3x) при х=4
0.9 * (-8) - 0.9*3x = -7.2 - 0.9*3x;
-7.2 - 0.9* 3*4 =-7.2 - 10.8 = -18
6)-1/4 * (4/5 у + 9) =-1/5у - 9/4 = -1/5 * 3 3/4 - 9/4 = -1/5 * 15/4 - 9/4 = -15/5 * 1/4 - 9/4 = -3/4 - 9/4 = -(3 + 9)/4 = -12/4 = -3;
1%=1/100 части числа)))))))))