x + 60 = 30 + 70

x + 60 = 100

x        = 100 - 60 

x        = 40

x+60=30+70

x+60=100

x=100-60

x=40

k mk nhe

x+300=200.2

x+300=400

x=400-300

x=100

k mk di mk k lia

thanks

x+300=200x2

x+300=400

x=100

vậy x= 100.

x+ 500 = 400x  2

x + 500 = 800

x = 800 - 500

x = 300 

x + 500 = 400 x 2

x + 500 = 800

         x = 800 - 500

         x = 300

x + 2015 = 100 + 2016

x + 2015 = 2116

x = 2116 - 2015

x = 101

Mk nhanh nhất đó

K bạn rồi 

dap an la 101

x+90=80+30

x+90=110

x=20

vậy x=20.

kkkk mk.

x + 90 = 80 + 30

x + 90 = 110

x = 110 - 90

x = 20 

x + 500 = 60 x 10

x + 500 = 600

x = 600 - 500

x = 100

K mk nha

=>x+500=600

=>x=600-500

=>x=100

x + 80 = 60 + 30

x + 80 = 90

x = 90 - 80

x = 10

K mk nha

x+80=60+30

x+80=90

x=90-80

x=10

vậy x=10.

x + 90 = 90 + 10

x + 90 = 100

x        = 100 - 90

x        = 10

x + 90 = 90 + 10

x + 90 = 100

      x   = 100 - 90

      x   = 10

tk mk mk tk lại

\(x+85=65+25\)

\(x+85=90\)

           \(x=90-85\)

           \(x=5\)

x + 85 = 65 + 25

x + 85 = 90

       x  = 90 - 85

       x  = 5

tk đi rồi tk lại
 

400 + x = 500 + 300

400 + x = 800

          x = 800 - 400

          x = 400

400 + x = 500 + 300

400 + x = 800

         x = 800 - 400

         x = 400