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2 years ago

Two complex numbers have a sum of 14 and a product of 74. Write either of the two numbers.

Mathematics

2 answers:

Alex777 [14]2 years ago

7 0

9514 1404 393

Answer:

7 +5i or 7 -5i

Step-by-step explanation:

If the two numbers are represented by x and y, then ...

x+y = 14

xy = 74

Substituting for y, we have ...

x(14 -x) = 74

x^2 -14x +49 = -74 +49 . . . . . multiply by -1, complete the square

(x -7)^2 = -25 . . . . . . . . . . . write as a square

x -7 = ±√(-25) = ±5i . . . . take the square root

x = 7 ± 5i . . . . . . . . . . . add 7

One of the numbers is 7 +5i.

IrinaVladis [17]2 years ago

3 0

Answer:

Hello,

Step-by-step explanation:

The 2 numbers are roots of the equation:

U²-14U+74=0

Discriminant=14²-4*74=-100

<u>U=7-5i or U=7+5i</u>

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Answer:

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Step-by-step explanation:

To find if a point makes an equation true, just substitute its x and y values in in the equation and simplify.

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12 does equal 12, so (12,0) makes the equation true.

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12 does equal 12, so (3, -1) makes the equation true.

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Answer:

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Step-by-step explanation:

Since a plumber and his assistant work together to replace the pipes in an old house, and the plumber charges $ 30 an hour for his own labor and $ 20 an hour for his assistant's labor, and the plumber works twice as long as his assistant on this job, and the labor charge on the final bill is $ 2000, to determine how long did the plumber and his assistant work on this job the following calculation must be performed:

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