Respuesta :

200x-90=400x+10

200x = 400x +100

200x - 400x = 100

-200x = 100

x = 100/-200

x = -1/2

Hope this will help....

x=-2
200x-90=400x+10
-200x. -200x
-90=200x+10
-10 -10
-100= 200x
-100 -100
x =-2