X-25%x-300=900 We have set the unknown X as the total length of the railway.

75%x-300=900, then the equivalent relationship is:

75%x=900+ first week repair 300+ second week repair = total length of railway.

75%x= 1200, so the equation is listed -x-25% x-300 = 900.

X= 1600 I hope I can help you. I'm in grade one.

The total length of this railway is 1600 meters.