Iknow there will be a difference between the real answer and the estimated answer but the problem is i do not know how to someone pls ? thks a lot and the answer is correct right?

The answer to c is:

Since we are estimating the different values in the expression, the answer won't be the same since we did not use the exact numbers hat the problem has given us. Our answers will definitely be different if we use different values in our expression.

ANSWER: The answer is c) -5 and a very happy birthday to you