First, notice that 1/(x^2) = x^(-2)dy/dx = d/dx (x^(-2) + 4x)The derivative of the sum is the sum of the derivatives= d/dx (x^(-2)) + d/dx (4x)The derivative of x^n is nx^(n-1), for every real number n, and a constant gets in front of the deivative= -2 x^(-3) + 4 d/dx (x)= -2/(x^3) + 4