Решить уравнение 5/14x-12=4/21x-7,5
5/14Х-4/21Х=-7,5+12
(5•3)/(14•3)Х- (4•2)/(21•2)Х=12-7,5
15/42Х- 8/42Х=4,5
7/42Х=4,5
1/6Х=4,5
Х=4,5; 1/6
Х=4,5• 6/1
Х= 27
Проверка
5/14• 27- 12= 4/21• 27- 7,5
135/14- 12= 4/7• 9 -7,5
9 9/14 -12 = 36/7 - 7,5
-(12- 9 9/14)= 5 1/7 -7 1/2
- (11 14/14 - 9 9/14)= -(7 1/2 - 5 1/7)
- 2 5/14= -( 7 (1•7)/(2•7) - 5 (1•2)/(7•2) )
-2 5/14= -( 7 7/14- 5 2/14)
-2 5/14= -2 5/14