А) (2-17/12):(3/8-1/6)* 3 1/4= 9,1
1) 2-17/12=1 12/12 - 1 5/12 = 7/12
2) 3/8-1/6=9/24 - 4/24 = 5/24
3) 7/12 : 5/24 = 14/5
4) 14/5 * 3 1/4 = 14/5 * 13/4 = 91/10=9,1
б) (7/10-2/5)*(1/4+5/6):6 1/2 = 1/20
1) 7/10-2/5= 7/10-4/10=3/10
2) 1/4+5/6=3/12+10/12=13/12
3) 3/10 * 13/12 = 13/40
4) 13/40 : 6 1/2= 13/40 : 13/2 = 1/20
<span>(3/7 - 16/21) * 2 1/7 + (11/15 + 0,3) : 12 2/5 = -53/84,
1) 3/7 - 16/21 = 9/21 - 16/21 = -7/21 = -1/3,
2) -1/3 * 2 1/7 = -1/3 * 15/7 = -5/7,
3) 11/15 + 0,3 = 11/15 + 3/10 = 22/30 + 9/30 = 31/30 = 1 1/30,
4) 1 1/30 : 12 2/5 = 31/30 : 62/5 = 31/30 * 5/62 = 1/12,
5) -5/7 + 1/12 = -60/84 + 7/84= -53/84</span>
(х-11/12)-5/6=-1 1/3
х-11/12-10/12=-1 4/12
х=21/12-1 4/12
х=1 9/12-1 4/12
х=9/12-4/12
х=5/12 - это корень уравнения. Проверка:
5/12-11/12-10/12=-16/12=-4/3=-1 1/3. Все верно.
1 5/6x-2/3x+0,25x=1 1/6x+0,25x=1 1/6x+25/100x=1 5/12x
130/100=1,3
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