Answer:
differentiate (2x+5)^2(x-4) u must know that it is a product function
Using the product rule you have dy/dx=udv/dx+vdu/dx
Let (2x+5)^2 be u and (x-4) be v
To find du we use chain rule which is du/dx=du/dw *dw/dx
We say let (2x+5) be w
We then have a new function like u=w^2
du/dw=2w
dw/dx=2
So du/dx=2*2w which equals 4w and w was (2x+5)
du/dx=4(2x+5)
dv/dx=1
So substitute everything into product rule we have
dy/dx=(2x+5)^2(1) + 4(2x+5)(x-4)
dy/dx=(4x^2 +20x+25) +(8x^2 -12x-80)
dy/dx=12x^2 +8x-55
dy/dx=(2x+5)(6x-11)