We can use the quadratic formula to solve this equation:
x = (-b ± √(b^2 - 4ac)) / 2a
where a, b, and c are the coefficients in the quadratic equation ax^2 + bx + c = 0.
Using the coefficients of the given equation, we get:
x = (-3 ± √(3^2 - 4(1)(-3))) / 2(1)
x = (-3 ± √21) / 2
Therefore, the two values of x that are roots of the equation x^2 + 3x - 3 = 0 are:
x ≈ -3.79 and x ≈ 0.79
Note that we rounded the values to two decimal places.