When you differentiate with respect to x, dy/dx, you multiply the number in front of the x by the power of the x then you take one away from the power.So for this example, the 2x5 differentiates to:(2x5)x(5-1) which is equal to 10x4.When you differentiate a number (which is not involving x) the number disappears. So for this example, the 7 (= 7x0) differentiates to:(7x0)x(0-1) which is equal to 0.So overall, dy/dx=-10x4