3) 7,1 – 2,6 + 1,34 = 5,84
№ 5
х – 2 1/24 = 7 5/12 – 4 11/18
х – 2 1/24 = 7 15/36 – 4 22/36
х – 2 1/24 = 6 (36+15)/36 – 4 22/36
х – 2 1/24 = 2 29/36
х = 2 1/24 + 2 29/36
х = 2 3/72 + 2 58/72
х = 4 61/72
111,11 : (20,45- 0,92х)- 3,2 = 51
111,11:(20,45-0,92х)=51+3,2
111,11:(20,45-0,92х)=54,2
20,45-0,92х=111,11:54,2
20,45-0,92х=2,05
-0,92х=2,05-20,45
-0,92х=-18,4
х=-18,4:(-0,92)
<span>х=20</span>