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egoroff_w [7]
4 years ago
7

Find the sum of the even integers between 21 and 45

Mathematics
2 answers:
Vika [28.1K]4 years ago
6 0
22+24+26+28+30+32+34+36+38+40+42+44= 396
mario62 [17]4 years ago
4 0

Solution:

we have been asked to find the sum of the even integers between 21 and 45.

The even integers between 21 and 45 is

22, 24, 26,28, 30, 32, 34, 36,38, 40, 42,44.

its forming an arithmetic progression with

first term=22=a

number of term=12=n

common difference=24-22=2=d

The sum can be found using the formula

S_n=\frac{n}{2}[2a+(n-1)d]\\

Substitute the values in the above formula we get

S_{12}=\frac{12}{2}[2*22+(12-1)2]\\ \\ S_{12}=6[44+22]\\ \\ S_{12}=6*66\\ \\S_{12}=396\\


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Answer:

Sum of cubes identity should be used to prove 35 =3+27

Step-by-step explanation:

Prove that : 35 = 8 +27

Polynomial identities are just equations that are true, but identities are particularly useful for showing the relationship between two apparently unrelated expressions.

Sum of the cubes identity:

a^3+b^3=(a+b)(a^2-ab+b^2)

Take RHS

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We can write 8 as 2 \times 2 \times 2 = 2^3 and 27 as 3 \times 3 \times 3 = 3^3.

then;

8+27 = 2^3+3^3

Now, use the sum of cubes identity;

here a =2 and b = 3

2^3+3^3 = (2+3)(2^2-2\cdot 3+3^2)

or

2^3+3^3 = (5)(4-6+9) = 5 \cdot 7 = 35 = LHS    proved!

therefore, the Sum of cubes polynomial identity should be used to prove that 35 = 8 +27

4 0
3 years ago
Read 2 more answers
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answer:

the first one and the last one

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7 0
3 years ago
45 degreese is used in a pie chart to reperesent 6 people. How many people were there altogehter?
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4 years ago
Find S16 for 1 + 7 + 13 + 19 +
amm1812

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7 0
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