Answer:
Step-by-step explanation:
Answer:
Steps shown below
Step-by-step explanation:
We will simplify this using definitions and identities. Let's start.

Using
, we have:

Using
, we have:

Hence, proved.
Answer:
$76.8
Step-by-step explanation:
As, So 20% of 64 will be the markup price.
So 20/100 x 64 = $12.8
Now Markup price = $12.8
And The retail price = markup price + original price = $12.8 + $64 = $76.8