Differentiate 3x^2 + 4x - 7

In order to differentiate a number, 2 steps are needed to be made. The first is to reduce the power of the number by 1 and then multiply that value to the first number. I will run you through the given question to explain this more clearly.
The first number we have is 3x^2. So by following the rules stated above, the first thing needed to do is to reduce the power by 1 and so the 2 in 3x^2 will become 1 so produce 3x. The next and final step is to bring the number in the power down and then multiply it by the original number. In this case the original power was 2 and so we need to mulitply 2 by 3 to produce 6. And so differentiating 3x^2 will produce 6x. We can now try this with the next number which is 4x. The power of the number will become 0 and the 4 will be needed to be multiplied by 1 so produce 4. Finally the -7 has no x value to it and so will disappear. Putting this all together; differentiating 3x^2 + 4x - 7 produces
6x + 4