а то я с ума сойду уже. 618.решите уравнение:
1)(1-7/10)x=2 1/4;
2)(1/4+1/5)x=1 4/5;
3)(3 1/8+1 3/4)x=2 1/6;
4)(2 1/12-1 5/6)x=3/4.

(1-7/10)х = 2 1/4

х - 7/10 х = 9/4

3/10 х = 9/4

х = 9/4 : 3/10 = 9/4 * 10/3 = 15/2 = 7 1/2

(3 1/8 + 1 3/4) х = 2 1/6

(25/8 + 7/4)х = 13/6

39/8 х = 13/6

х = 13/6 : 39/8 = 13/6 * 8/39 = 4/9

(1/4+1/5)х = 1 4/5

9/20 х = 9/5

х = 9/5 : 9/20 = 9/5 * 20/9 = 4

(2 1/12 - 1 5/6) х = 3/4

(25/12 - 11/6) х = 3/4

1/4 х = 3/4

х = 3/4 : 1/4 = 3/4 * 4/1 =3