Question

That is the screen shot for questions 5.

Answer 1

It's choice C as the root overhead bar goes over all of (x-7) and not just the x. So you have the correct answer. 

f(x) = x^4+7
y = x^4+7
x = y^4+7
y^4 = x-7
y = FourthRoot(x-7)

$y = \sqrt[4]{x-7}$