20 + 20 + 20 + 20 + 20 + 50 + 50 + 50 + 50

= 20 x 5 + 50 x 4

= 100 + 50 x 4

= 100 + 200

= 300

x + 50 - 20 = 50 + 20

x + 50 - 20 = 70

x + 50 = 70 + 20

x + 50 = 90

x = 90 - 50

x = 40

Ủng hộ tíck mik nha !!! 

tính nhanh

20 + 20 + 20 + 20 + 20 + 50 + 50 + 50 + 50

= (20 x 5) + (50 x 4)

=       100  +     200

=          300

tìm x:

x + 50 - 20 = 50 + 20

x + 50 - 20 = 70

x + 50        = 70 + 20

x + 50        = 90

             x   =  90 - 50

             x    = 40

tchs mik tchs lại

Tính nhanh: 

20 + 20 + 20 + 20 + 20 + 50 + 50 + 50 + 50

= 20 x 5 + 50 x 4 

= 100 + 200

= 300

Tìm x: 

x + 50 - 20 = 50 + 20

x + 50 - 20 = 70

x + 50 = 70 + 20

x + 50 = 90

x = 90 - 50

x = 40

x+20=20+50+50

x+20=120

x=120-20

x=100

k nhé trang rùi mình k lại

x + 20 = 20 + 50 + 50

x + 20 = 70 + 50

x + 20 = 120

x        = 120 - 20

x        = 100

x +20 = 20 +50 +50

x + 20 = 120

x = 120 - 20

x = 100

2500

2400

1000

50 x 50=2500

60x40=2400

50x20=1000

tick mk nha bạn  

2500

2400

1000

x + 20 = 50 + 50 + 50

x + 20 = 50 x 3

x + 20 = 150

=> x   =  130.

x+20=3x50=150

x=150-20=130

x=130

thu lai 130+20 = 50+50+50=150

x + 20 = 50 + 50 + 50

x + 20 = 150

x        =  150 - 20

x        =     30

50+50+50x100-20

=50x3x100-20

=150x100-20

=15000-20

=14980

50 + 50 + 50 x 100 - 20 = 50 x 100 + 50 + 50 - 20 = 5000 + 50 + 50 - 20 =5100 - 20 = 5080

hoặc là 50 + 50 + 50 x 100 - 20 = 50 x 2 + 50 x 100 - 20 = 5100 - 20 = 5080

a) Ta có B (12) = {0;12;24;36;48;60;72,..}. Mà 20 ≤ x ≤ 50 ;

=> xϵ {24;36;48}.

b) x ϵ {10;20}.

c) x ϵ {0;7;14;21;28;35;42;49}.

d) x ϵ {1;2;3;4;6;12

= ( 60 + 50+40+30+20+10 ) x 2000 + 1500

= 210 x 2000 + 1500

=  420000 + 1500

= 421500

= 421500 nha bn, nhớ k mk nha

=421500

x+50=50+20

x+50=70

x=20

vậy x=20.

x + 50 = 50 + 20

x + 50 = 70

        x = 70 - 50

        x = 20

ai k mk mk k lại ^_^

trao đổi k nhìu càng tốt ^_^

x + 50 = 50 + 20

x + 50= 70

        x= 70 - 50

       x = 20

tk nha ban tk bn rùi đó

x + 50 = 20 + 50

x + 50 = 70

x = 70 - 50

x = 20

x + 50 = 20 + 50

x + 20  = 70

x         = 70 - 20

x         = 50

x+50=20+50

x+50=70

x=70-50

x=20

x - 20 = 50 + 50

x - 20 = 100

       x = 100 + 20

       x = 120

tk nha

x - 20 = 50 + 50

x - 20 = 100

x       = 100 + 20

x       = 120

x-20=100

x=100+20

x=120

ai tk mk mk tk lai