Question

Find
dy/du, du/dx, and dy/dx

y= u^2 , u=4x+7

Answer 1

y=u²                    (du/dx[u^n]=n(u^(n-1))u`)
dy/du=2u(u´)=2u

u=4x+7
du/dx=4

dy/dx=(dy/du)(du/dx)=2u(4)=2(4x+7)(4)=8(4x+7)

Answer:
dy/du=2u
du/dx=4
dy/dx=8(4x+7)

Answer 2

dy/dx =2u
du/dx==4
 
and
dy/dx= (dy/du)(du/dx)
         =2u(4)
         = 8u