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asambeis [7]
4 years ago
10

Please help!!!!

Mathematics
1 answer:
nlexa [21]4 years ago
3 0

Answer:

225

Step-by-step explanation:

Using the basic components of summation ∑

∑n = \frac{1}{2} n(n + 1) and ∑1 = n

Thus

∑ (2n - 1) ← for n = 1 to 15

= ∑2n - ∑1

= 2∑n - ∑1

= 2 (\frac{1}{2} n(n + 1)) - n

= n(n + 1) - n ← Evaluate for n = 15 ( the upper value )

= 15 × 16 - 15

= 240 - 15

= 225

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70% of what number is 595?<br> Please help
MA_775_DIABLO [31]

Answer:

850

Step-by-step explanation:

We have, 70% × x = 595

or,  

70

100

× x = 595

Multiplying both sides by 100 and dividing both sides by 70,

we have x = 595 ×  

100

70

3 0
3 years ago
Read 2 more answers
2x - y = 11<br> 6x – 3y = 15 <br> solve for x and y using elimination
Yanka [14]

Answer:

Step-by-step explanation:

Given the simultaneous equation

2x - y = 11. Equation 1

6x – 3y = 15. Equation 2

Using elimination method

Multiply the coefficient of x in equation 1 (which is 2) to equation 2. Also, multiply the coefficient of x in equation 2 (which 6) to equation 1. By doing this we are going to eliminate x

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6x – 3y = 15. ×2 Equation 2

12x-6y=66. Equation 3

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Subtract equation 4 from 3

Then (12x-6y) - (12x-6y) =66 -30

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8 0
3 years ago
(2x²+3)(3x-2)-3x(x²-4)<br>​
ivann1987 [24]

Answer:

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Step-by-step explanation:

i hope this is right<3

4 0
2 years ago
There are 2 Senators from each of 50 states. We wish to make a 3-Senator committee in which no two members are from the same sta
Morgarella [4.7K]

Answer:

a) rCn = 1176

b) 2352

Step-by-step explanation:

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6 0
3 years ago
Rounding or compatible numbers to estimate the sum 620+107=
Rudik [331]
You could do 600+100=700 because it would be close to the actual rusult
6 0
4 years ago
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