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2 years ago

The sum of two numbers is 39. Their difference is 21. What are the two numbers?

Mathematics

2 answers:

Yanka [14]2 years ago

6 0

Answer:

30 and 9

Eeexplination;

mrs_skeptik [129]2 years ago

4 0

Answer:

30 and 9

Step-by-step explanation:

x+y=39 , x-y=21

Solve for x:

x+y=39 , x-y=21

x= 30

Substitute x with 30:

(30)+y=39 , (30)-y=21

Solve for y:

y=9

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masha68 [24]

Answer:

Please check the explanation.

Step-by-step explanation:

Given the vector

v = 6i + 2√3j

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$\mathrm{Computing\:the\:Euclidean\:Length\:of\:a\:vector}:\quad \left|\left(x_1\:,\:\:\ldots \:,\:\:x_n\right)\right|=\sqrt{\sum _{i=1}^n\left|x_i\right|^2}$

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$=\sqrt{36+12}$

$=\sqrt{48}$

$\mathrm{Apply\:radical\:rule}:\quad \sqrt[n]{ab}=\sqrt[n]{a}\sqrt[n]{b}$

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The Direction of a vector:

tan Ф = y/x

y=2√3

x = 6

tan Ф = y/x

= 2√3 / 6

= √3 / 3

$\theta \:=tan\:^{-1}\left(\frac{\sqrt{3}}{3}\right)$

$\:\theta \:=\frac{\pi \:}{6}=30^{\circ \:}$

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2 years ago

Which expression is equivalent to (sqrt3 + i)^3?

Anarel [89]

Express √3 + i in polar form:

|√3 + i| = √((√3)² + 1²) = √4 = 2

arg(√3 + i) = arctan(1/√3) = π/6

Then

√3 + i = 2 (cos(π/6) + i sin(π/6))

By DeMoivre's theorem,

(√3 + i)³ = (2 (cos(π/6) + i sin(π/6)))³

… = 2³ (cos(3 • π/6) + i sin(3 • π/6))

… = 8 (cos(π/2) + i sin(π/2))

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