To answer this question you must first plug in the given value for x into your given expression.
Your given x value is a -3.
When plugged in, this leaves you with:
-3^2 + 4(-3) + 3
Next, follow PEMDAS (parenthesis, exponents, multiplication, division, addition, subtraction) to begin to simply your expression.
Start by multiplying the parenthesis, this leaves you with:
-3^2 - 12 + 3
After that, simplify your exponents by squaring the -3. You do this by multiplying it by itself.
This leaves you with:
9 - 12 + 3 (the 9 is positive because the two negative multiplied together cancelled to make a positive)
Finally, simplify across with addition and subtraction to get your final answer.
This results in:
0
So, when x = -3 in this expression, the answer is 0.
I hope this helps! :)