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3 years ago

10^2+12^2+14^2+......+26^2=??

Mathematics

1 answer:

Kazeer [188]3 years ago

3 0

Answer:

3156

Step-by-step explanation:

<em>Used formula:</em>
<em>(1² + 2² + 3² + ... + n²) =1/6*n(n + 1)(2n + 1)</em>

--------

10²+12²+14²+......+26² =
(2*5)²+(2*6)² + (2*7)² + ... + (2*13)² =
4*(5²+6²+7²+...+13²) =
4*(1²+2²+...+13² - (1²+2²+3²+4²)) =
4*(1/6*13(13+1)(2*13+1) - (1+4+9+16)) =
4*(1/6*13*14*27- 30) =
4*(819 - 30) =
4*789 =
3156

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3 years ago

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Let r and s be the roots of x^2 - 6x + 2 = 0. Find (r - s)^2.

Sphinxa [80]

Answer: $(r-s)^{2} = 28$

Step-by-step explanation:

$x^{2} -6x+9=-2+9$
$(x-3)^{2}=7$
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$[(3-\sqrt{7})-(3+\sqrt{7})]^{2}$
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3 years ago

What is the value of x? tangent lines acellus

liberstina [14]

Answer:

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Step-by-step explanation:

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11111nata11111 [884]

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483: 480 and 500.

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Ulleksa [173]

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Step-by-step explanation:

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