To simplify the expression (1-√x) x (1+√x+ x), we can use the distributive property of multiplication over addition:

(1-√x) x (1+√x+ x) = 1 x (1+√x+ x) - √x x (1+√x+ x)

Now, let's simplify each term separately:

1 x (1+√x+ x) = 1 + √x + x

√x x (1+√x+ x) = √x + x√x + x^2

Now, let's combine the simplified terms:

(1-√x) x (1+√x+ x) = (1 + √x + x) - (√x + x√x + x^2)

Next, let's simplify further:

(1 + √x + x) - (√x + x√x + x^2) = 1 + √x + x - √x - x√x - x^2

Now, let's combine like terms:

1 + √x - √x + x - x^2 - x√x = 1 + x - x^2 - x√x

Therefore, the simplified expression is 1 + x - x^2 - x√x.