1) 4*х-5/9 х=3.6

2) 24 4/5 - 19.5 : 7 2/9

3) 2.4+5.6 * (13 3/4 - 12 13/14)

1) 4 х-5/9 х=3.6

3 4/9 х=3,6

х=3,6 : 3 4/9

х=3,6 : 31/9

х=3,6 * 9/31

х=32,4/31

х=324/310

х=1 14/310

х=1 7/155

2) 24 4/5 - 19.5 : 7 2/9=

24 4/5 - 195/10 : 65/9=

24 4/5 - 195/10 * 9/65=

24 4/5 - 39/10 * 9/13=

24 4/5 - 351/130=

24 4/5 - 2 91/130=

24 104/130 - 2 91/130=

22 13/130 = 22 1/10

3) 2.4+5.6 * (13 3/4 - 12 13/14) =

2.4+5.6 * (13 21/28 - 12 26/28) =

2.4+5.6 * (12 49/28 - 12 26/28) =

2.4+5.6*23/28=

2.4+56/10*23/28=

2.4+2*23/10=

2.4+46/10=

2.4+4.6 = 7