Well 600-280=320 but if you're going for the neerest hundred that will be 300
(2x + 10)(x - 9)
2x(x - 9) + 10(x - 9)
2x(x) - 2x(9) + 10(x) - 10(9)
2x² - 18x + 10x - 90
2x² - 8x - 90
Answer:
40.92
Step-by-step explanation:
hope this helps
Answer:
= 4374.
Step-by-step explanation:
it is important to understand the pattern hidden in such problem.Let’s give it a try 2, 6, 18, 54 and so on.It can be written as 2, 3*2, 9*2, 27*2 and so on.
This can be further written as2 (1, 3, 9, 27, and so on) as 2 is common in every term.Now if you see the chain 1,3,9, 27 and so….you will see a pattern hidden i.e. 3=1*3 ,9=1*3*3, 27=1*3*3*3 now 27 is the 4th term consist of three 3. So 8th term would consist of seven 3. 8th would be 8th term = 1*3*3*3*3*3*3*3 = 2187 Hence the 8th term for the series 2,6,18,54 would be= 2*2187 = 4374.
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.
