(x^2 + x) / x-3x . 4 =

To simplify the expression (x^2 + x) / (x-3x) * 4, we need to follow the order of operations, which is also known as the PEMDAS rule (Parentheses, Exponents, Multiplication, Division, Addition, Subtraction).

1. First, let's simplify the expression inside the parentheses. The numerator is (x^2 + x), which cannot be simplified further. The denominator is (x-3x). We can simplify it by combining similar terms:
(x - 3x) = -2x

2. Now our expression becomes (x^2 + x) / (-2x) * 4.

3. Next, let's perform the multiplication. Multiply each term of the numerator, (x^2 + x), by 4:
4 * (x^2 + x) = 4x^2 + 4x

4. The expression now becomes (4x^2 + 4x) / (-2x).

So, (x^2 + x) / (x-3x) * 4 simplifies to (4x^2 + 4x) / (-2x).