This is a quadratic equation. To solve it, first let's simplify the equation by combining like terms:

x^2 + 3x - sqrt(x^2 + 3x) - 2 = 0

Next, let's isolate the square root term by moving all other terms to the other side of the equation:

x^2 + 3x - 2 = sqrt(x^2 + 3x)

Now, square both sides of the equation to eliminate the square root:

(x^2 + 3x - 2)^2 = x^2 + 3x

Expanding the left side gives:

(x^2 + 3x - 2)(x^2 + 3x - 2) = x^2 + 3x

x^4 + 3x^3 - 2x^2 + 3x^3 + 9x^2 - 6x - 2x^2 - 6x + 4 = x^2 + 3x

Combine like terms:

x^4 + 6x^3 + 5x^2 - 9x + 4 = x^2 + 3x

Rearrange to set the equation equal to zero:

x^4 + 6x^3 + 4x^2 - 6x + 4 = 0

This is the simplified form of the equation.