1)
2/35 - 2.9x= 0.8x - 3/14
-2,9х -0,8х= -3/14 - 2/35
-3,7 х = - 15/70 - 4/70
-3,7х= -19/70
х= -19/70 : (-37/10) = (19*10)/ (70*37)
х= 19/259
2/35 - 2,9 * 19/259 = 0,8 * 19/259 - 3/14
2/35 - 551/2590 = 152/2590 - 3/14
(148-551) / 2590 = (152- 555) /2590
-403/2590 = -403/2590
2)
-0,21х - 15/56 = 3/16 + 257/800 х
-0,21 х - 257/800 х = 3/16 + 15/56
х ( - 21/100 - 257/800) = 21/112 + 30/112
х ( - ( 168+ 257) / 800) = 51/112
-425/800 х = 51/112
- 17/32 х = 51/112
х= 51/112 : (-17/32) = -(51*32) / (112*17)= - (3*2) / ( 7*1)
х= - 6/7
-0,21 * (-6/7) - 15/56 = 3/16 + 257/800 * (-6/7)
(21*6)/ (100*7) - 15/56 = 3/16 - (257*6)/ (800*7)
9/50 - 15/56 = 3/16 - 771/2800
(252-375) / 1400 = (525-771)/2800
-123/1400 = - 246/2800
-123/1400 = - 123/1400