First, consider that a trasnlation of a function f(x), a units to the left, is represented by the function f(x + a). Moreover, take into account that a vertical translation of a function cosists in adding a constant in the form f(x) + b, where b is the constant.
Then, for the function G(x) = x², you can notice that the function has been traslated to the left 3 units, furthermore, the function concavity opens downward (which means that the dominant coefficient is negative) and there is a vertical translation of 3 units. These operations can be written as follow:
F(x) = -3(x + 3)² + 3