Respuesta :
We know that f(x) = 7x + 8. So, take the derivative of this function with respect to x.
This gives
f'(x) = 7
Now, you probably realized that the x value disappeared. This means that no matter what value of x you use, the derivative of this function is always going to be 7, even at x = 5. That is, the rate of change of this function is always going to be a rate of 7.
2x + 7 as the you use the power rule to find the derivative of x^2 and 7x, since -4 is a constant the derivative of it would be 0