a,1/5+4/5:X=0,75 b,X+1/2=1-X

1/5+4/5:X=3/4-1/5 2X=1-1/2

4/5:X=11/20 2X=1/2

X= 16/11 X=1/4

Vậy X=16/11 Vậy x=1/4

a,2/3.5/4-3/4.2/3=2/3.(5/4-3/4)=2/3.1/2=1/3

b=2.9/2-7/2=1

c-3/4.68/13-3/4.36/13=/3/4.(68/13+36/13)=-3/4.8=-6

a,(1/2+1,5).X=1/5

2.X=1/5

X=1/5:2

X=1/10

Vậy=1/10

b,(-8/5+X):12/13=13/6

-8/5+X=13/6.12/13

X=2+-8/5

X=18/5

VẬY X=18/5

c,(X:3/7)=-3/8

X.3/7.1/7=-3/8

X=-3/8:3/49

X=-49/8

Vậy x=-49/8

d,-4/7.X+7/8=1/8:(-3/5)

-4/7X+7/5=1/8.-3/5

-4/7X=-3/40:-4/7=413/160

Vậy x=413/160

a,X+1/3=1/2-5/6 b,3/8+5/8-1/5-X=1/5

X=-1/3-(1/3) X=1-1/5-1/5

X=-2/3 X=3/5

Vậy x=-2/3 Vậy=3/5

a,X=7-2/5+1,62 b,X=23/5+1/5-1/2

X =2/155 X=43/10

Vậy X=2/155 Vậy=43/10

c,X=2X-X d,X=7/2-5/7+1/13-0,25

X=3/5+4/7 X=951/364

X=41/35 Vậy=951/364

VậyX=41/35

A=[2/7.(1/4-1/3)]:[2/7.(1/3-2/5)]=(1/4-1/3):(1/3-2/5)=5/4

B=3/4.(1/5-2/7-1/3+2/7)/1/5.(2/7+1/3)-1/3.(2/7+1/3)=63/52

P=2/3+1/4+3/5-7/45+5/9+1/12+1/35=(2/3+1/4+1/12)+95/9-7/45)+3/5=1+4/5+3/5+1/35=71/35

Q=(5-6-2)+(-3/4-7/4+5/4)+(1/5+8/5-16/5)=-(3+5/4+7/5)=-113/20

A=3/5.6/7=3/5.3/7-2/7.3/5

=3/5.(6/7+3/7-2/7)

=3/5.1

=3/5

B=(-1.2/5+-2/9:5/2+2/5.11/9).2/5

=(-13.2/5+-2/9.5/2=2/5.11/9).5/2

=(-13+-2/9+11/9)2/5.5/2

= -13+(-2/9+11/9)

=-13+1

=-12

C=(-4/5+5/7).3/2=(-1/5-2/7).3/2

=(-4/5+5/7+-1/5-2/7).3/2

=(-4/5=-1/5=5/7+2/7).3/2

=(-1+1).3/2

=0

D=4/9:(1/15-10/15)+4/9:(2/22-5/22)

=4/9:-3/5+4/9:3/22

=4/9.(-5/3+-22/3)

=4/9.(-9)

=-4

A=(13+23)-(815+715)+(-17+117)=1-1+1=1

B=(0,25-114)+(35+25)-18=-0,125