Answer:
14
Step-by-step explanation:
In the question, the given expression is

And we have to find the equivalent expression to the given expression .
First we remove the parenthesis

Now we combine the like terms, and here like terms are z and z, therefore on combining , we will get

And that's the required equivalent expression .
I think your answer is right.
A, B and D are already rational numbers, 0.4 itself is a rational number, two rational numbers make a product of rational number.
So A, B, D are the correct choices.
Are you sure it asks for rational numbers, not irrational number?
If it is on sale for 15%, then you are paying 85% (100-15) of the original price.
To find 85% of 850, you do 850*.85 to get $722.50
Hope this helps