Answer:
22.5
Step-by-step explanation:
If you expand the series, you can see the first few terms of the series:
- Putting 1 in
, 
- Putting 2 in
, 
- Putting 3 in
,
- Putting 4 in
,
We can see the series is 0, 0.5, 1, 1.5, ....
This is an arithmetic series with common difference (the difference in 2 terms) 0.5 and first term 0.
We know formula for sum of arithmetic series:

Where,
denotes the nth partial sum
is the first term (in our case it is 0)
is the term (in our case it is 10 since we want to find 10th partial sum -- sum until first 10 terms)
is the common difference (difference in term and the previous term) (in our case it is 0.5)
Substituting these into the formula, we get the 10th partial sum to be:

So the sum of the first 10 terms is 22.5. Third answer choice is right.
8x² - 4 = 28
8x² = 28 + 4
8x² = 32
x² = 32/8
x² = 4
x = <span>±2
</span>
Answer: x = -5, 3/2 y = 10, 7/2
Explanation:
y = 2x^2 + 6x - 10 (1)
y = - x + 5 (2)
=> 2x^2 + 6x - 10 = - x + 5
2x^2 - 7x - 15 = 0
(2x - 3)(x + 5) = 0
=> 2x - 3 = 0
2x = 3
x = 3/2
=> x + 5 = 0
x = -5
According to (2):
y = -x + 5
y = -(-5) + 5
y = 5 + 5 = 10
y = -x + 5
y = -(3/2) + 5
y = -(3/2) + 10/2
y = 7/2
Simply the answer is 7 ounces :D
Rational numbers are closed under addition ,multiplication but not closed under division
Rational number
Closure property
assume two rational numbers say x and y. the results of addition and multiplication operations give a rational number we can say that rational number are closed under addition and multiplication . For example
rational number are not closed under division as 1 and 0 are rational number but 1/0 is not defined but it is closed under addition and multiplication
that is 1+0 = 1 closed under addition
1*0 =0 closed under multiplication
but 1/0 is not defined so it is not closed under division
Hence Rational numbers are closed under addition ,multiplication but not closed under division
learn more of closure property here
brainly.com/question/28220649
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