Which line shows the first error in the solution?

a.
line 3

b.
line 4

c.
line 5

d.
line 6

(if f(x)=4x^2 and g(x)=x+1, find (f o g)(x)

What is the value of x in the diagram below?

Someone answer asap for ! michele pushes a box d meters across a floor. she uses a force f, in newtons, to push the box. she pushes the box for t seconds. the formula p = fd/t calculates the power, p, in watts, that it takes for michele to complete the task. solve the formula for d.