Can you explain how to negate a sentence?
If you are trying to negate a sentence such as I don't like sandwiches, you use the ne...pas construction. For example I do not like the pizza would be Je n'aime pas la pizza. That is the example in the present and its the same in the imparfait. For the passé composé, you put the auxiliary verb in between the ne...pas and then the past participle after. Using the previous example it would be je n'ai pas aimé la pizza. So that's how you use negation in the three main tenses!
evaluate the integral of 2/1+x^2
The easiest way to evaluate an integral is to put it in the simplest terms as possible. When you have an integer in the numerator by itself you can always move it outside and then just multiply it at the end. After moving the 2 to the outside you might be thinking that an x^2 should warrant a u-sub but this is a different case. When you see anything + x^2 in the denominator it is often results in a trigonometric answer. In this case with 1+x^2 the answer is arctanx+C. This form would be one that requires memorization for the future. Then you need to remember the 2 from the earlier part to get 2arctanx+C
Can you please explain how you multiply this? (2x+7) x (x+4)
When you think about how to factor the first thing to remember is the FOIL method. This means that you multiply the 2x and the x (first) the 2x and the 4 (outer) then the 7 and x (inner) and then to end the 7 and the 4 (last). After this you add together all the elements. Then as long as you keep the signs straight you should be left with the correct answer. In this case 2x^2 +15x+28.