Differentiating both sides of

with respect to <em>x</em> yields (using the chain rule)

Solve for d<em>y</em>/d<em>x</em> :

The answer is then D.
Answer:
C. 88
Explanation:
f(x) = 4x + 8 || g(x) = x² + x
fg( -5 )
go from right to left in such function problems.
replace x with [ -5 ]
f( (-5)² -5)
f(20)
[ replace x with 20 ]
4(20) + 8
80 + 8
88
0.0000213, that should be it.