Answer:
See explanation below
Step-by-step explanation:
<em>R(x,y) means x and y are related</em> according to previous established relation.
For example R(x,y) could be “x<y” if x, y are integer numbers, or R(x,y) could be “x and y are friends” if x and y are people.
<em>The set which x and y belongs to, need not be the same.</em>
<em>∀x∀y R(x, y) means: for every x in a set S and every y in a set T, x and y are related.
</em>
The logical conector “and” is commutative, that is to say, the sentence “for every x in a set S and every y in a set T x and y are related” is the same as “for every y in a set T and every x in a set S x and y are related”.
This last sentence is ∀y∀x R(x, y).
So, they are the same thing.
I can’t see A-c can u take another picture
Original cost is $80.
Original cost is denoted by 100%
$80 represent 100%
$1 represent 100 ÷ 80 = 1.25%
Saving is $12
$12 represent 1.25 x 12 = 15%
So $12 represent 15%