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.
<span> 20% of 40 is 8. so 40</span>
Answer: 14
Step-by-step explanation:
20% of 60=12
20% of 10=2
12+2=14
Cost of air cooler:-3,300
vat added:- 5%
so, price before vat was added:-5/100×3,300=AED165