Step-by-step explanation:
sum of the arithmetic sequence
a1 = 8
a2 = a1 + 8 = 8+8 = 16
...
an = 8×n
the sum of the first n elements of such a series is
n/2 × (2×a1 + (n - 1)×d]
with d being the difference between 2 consecutive elements (= the added constant).
so,
s30 = 30/2 × (2×8 + 29×8) = 15×(31×8) = 3720
To factor first multily 100 and 1 and get 100
then find what 2 numbers multiply to get 100 and add to get 20
the numbers are 10 and 10
so
split the center term up
100x^2+10x+10x+1
group
(100x^2+10x)+(10x+1)
undistribute
(10x)(10x+1)+(1)(10x+1)
undistribute/reverse distributive property
(10x+1)(10x+1)
(10x+1)^2
Answer:
-2; -7
Step-by-step explanation:
Hello, the graph is split in two lines, right?
Go to the first line at the left and move to the right until you reach the end of the line, which is for x = -1,
*** This is the meaning of x tending to
***
which value can you see for the y-axis? 
Now, go to the second line at the right and move to the left until you reach the end of the line, which is for x = -1,
*** This is the meaning of x tending to
***
which value can you see for the y-axis?

Thanks
Answer:
284.625
Step-by-step explanation:
Arrange the numbers highest to lowest.
Find the middle value in the arrangement.
Answer:
Step-by-step explanation:So we know x + y = 21 and 5x +10y = 165 We line them up in columns x + y = 21 5x +10y = 165 To eliminate the x variable, I'll multiply every element in the 1st equation by -5. -5x + -5y = -105 5x + 10y = 165 Now we combine (add) the equations, which eliminates x altogether. 5y = 60 ... y = 12 From there, x + 12 = 21 ... x = 21-12 ... x = 9 You should double check. Do 9 nickles and 12 dimes equal $1.65? A very important thing to remember using this method is to do the same thing to each element in the equation that you change! I hope that helps.