show that y= x + e^x is a solution of dy/dx = y - x +1
if y = x + e^x , then
dy/dx = 1 + e^x
but from the equation
y = x + e^x
e^x = y-x
so sub that into the above dy/dx and you got it
dy/dx = 1 + e^x
but from the equation
y = x + e^x
e^x = y-x
so sub that into the above dy/dx and you got it