Помогите решить

1) (x-2,3) - 4 при х=1,5

2) (3 х + 1 целая 4/15) + 2/3 при х=1,2

3) 11 + (3/8x - 5/6) при х=4,9

4) 8/9 + (1/12x-7/9) при х = - 4

1) (x-2,3) - 4 при х=1,5; (1,5-2,3) - 4; 4 - (-0,8) = 4+0,8=4,8; 2) (3 х + 1 целая 4/15) + 2/3 при х=1,2; (36/10+1 4/15) + 2/3; (18/5+19/15) + 2/3; (54/15+19/15) + 2/3; 73/15+2/3; 73/15+10/15; 83/15; 5 целых 8/15 3) 11 + (3/8x - 5/6) при х=4,9; 11 + (3/8*49/10-5/6); 11 + (147/80-5/6); 11 + (441/240-200/240); 11+241/240; 12 целых 1/240 4) 8/9 + (1/12x-7/9) при х = - 4; 8/9 + (-1/3-7/9); 8/9-10/9; - 2/9