The answer to increasing 84 by 20% is 100.8
Commutative - addition.
You're switching a and b to get the same answer. It works with Multiplication too, as you can tell!
Answer:
Length = 
Breadth = 
Step-by-step explanation:
Let
be the length of the garden
and
be the width of the garden
From the details of the cost in the question we get

Now area of the garden is

Differentiating with respect to x we get

Equating with 0

Double derivative of the area is

So, area is maximum at 

So, the length and breadth of the rectangle is
.
Answer:
60480
Step-by-step explanation:

The correct answer is 30 am pretty sure about it