уравнение:1)0,2*(5x-2)=0,3*(2x-1)-0,9; 2)1/3y+5/12y=7,2; 3)x-5/8x=2,4; 4)1,3:3,9=x:0,6; 5)x+3,12=-5,43; 6)5,23+x=-7,24; 6)y-2целые5/12=-3целые7/12; 7)0,3(x-2)-0,2(x+4)=0,6; 8)0,6(x+7)=0,5(x-3)+6,8; 9)0,5(x-3)=0,6+0,2(x+4); 10)3/14x-0,59=8/21x-1,24; 11)3/14x-0,59=8/21x-1,24; 12)1,2+3/10y=8/15y+0,

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Ответы и объяснения

2012-04-16T12:17:45+00:00

0,2*(5х-2)=0,3*(2х-1)-0,9                      x-5/8x=2,

1х-0,4=0,6x-0,3-0,9                              8/8x-5/8x=2                      

1x-0.4=0,6x-1,2                                     3/8x=2

x-0,6x= -1,2+0,4                                    x=2:3/8

0,4x=-0,8                                              x=2 *8/3

x=-0,8:0,4                                            x=16/3

x=-2                                                     x=5 1/3

 

1/3y+5/12y=7,2                                      1,3:3,9=x:0,6(здесь вроде что-то не то)

1/3+5/12=4/12+5/12=9/12=3/4    наверно  3,9:1,3=x:0,6

3/4y=7,2                                                        3=x:0,6

y=7,2:0,75 =(3/4)                                          3*0,6=x

y=9,6                                                             x=1.8  проверяем  3=1,8:0.6