x+100=200-700+100

x+100=-500+100

x+100=-400

x=-400-100

x=-500

x + 100 = 200 - 700 + 100

x + 100 = - 500 + 100

x + 100 = - 400

x          = - 400 - 100

x          = - 500

4947300 do ban

h minh  nha

x + 100 = 600 + 300

x + 100 = 900

x             = 900 - 100

x             = 800

h minh nhA