Answer:
Step-by-step explanation:
As the statement is ‘‘if and only if’’ we need to prove two implications
is surjective implies there exists a function
such that
.- If there exists a function
such that
, then
is surjective
Let us start by the first implication.
Our hypothesis is that the function
is surjective. From this we know that for every
there exist, at least, one
such that
.
Now, define the sets
. Notice that the set
is the pre-image of the element
. Also, from the fact that
is a function we deduce that
, and because
the sets
are no empty.
From each set
choose only one element
, and notice that
.
So, we can define the function
as
. It is no difficult to conclude that
. With this we have that
, and the prove is complete.
Now, let us prove the second implication.
We have that there exists a function
such that
.
Take an element
, then
. Now, write
and notice that
. Also, with this we have that
.
So, for every element
we have found that an element
(recall that
) such that
, which is equivalent to the fact that
is surjective. Therefore, the prove is complete.

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Write the divide fraction horizontally:
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Factorise the numerators and denominators when possible:
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Convert the divide fraction to multiplication fraction
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Cancel the factors
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Combine to single fraction
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The simplified answer is
.
<u>Step-by-step explanation:</u>

To add or subtract denominators of the fraction must be same.
If it is not the same, we must take LCM of the denominators. and so we can add the fractions.
To make the denominator same multiply the 1st term
and 2nd term by 
= 
LCM of the denominators is 6x²+ 3xz + 2xy +yz.
Multiply the factors in the numerator.
= 
Now, the denominators are same, you can subtract it.
= 
= 
Thus the simplified solution is 
Answer:
1) x = 31
2) Both angles add up to be a supplementary angle (an angle who's sum is 180° altogether).
Step-by-step explanation:
1) Since both angles add up to be a supplementary,
→ equation 1 + equation 2 = 180
→ (3x + 25) + (2x) = 180
Solving by applying algebra will give the answer "x = 31".
Hope this helps!