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pickupchik [31]
3 years ago
6

What is the sum of the expression (8- 4 i) + (-2+7i)?

Mathematics
1 answer:
prohojiy [21]3 years ago
5 0

Answer:

The sum of the expression (8 - 4i) + (-2 +7i) is (6 + 3i)

Step-by-step explanation:

In the complex numbers (a + bi) and (c + di), we can add the real parts together and the imaginary parts together, so their sum is

(a + bi) + (c + di) = (a + c) + (b + d)i

Let us use this fact to solve our question

∵ The complex numbers are (8 - 4i) and (-2 + 7i)

∴ Their sum = (8 - 4i) + (-2 + 7i)

∵ The real parts are 8 and -2

∵ 8 + -2 = 8 - 2 = 6

∴ The sum of the real parts is 6

∵ The imaginary parts are -4i and 7i

∵ -4i + 7i = 3i

∴ The sum of the the imaginary parts is 3i

∵ (8 - 4i) + (-2 + 7i) = (8 - 2) + (-4 + 7)i

∴ (8 - 4i) + (-2 + 7i) = 6 + 3i

∴ The sum of the expression (8 - 4i) + (-2 +7i) is (6 + 3i)

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Find the value of c that completes the square for x2−15x+c
meriva

Answer:

The value of <em>c</em> is \frac{225}{4}.

Step-by-step explanation:

The perfect square of the difference between two numbers is:

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The expression provided is:

x^{2}-15x+c

The expression is a perfect square of the difference between two numbers.

One of the number is <em>x</em> and the other is √<em>c</em>.

Use the above relation to compute the value of <em>c</em> as follows:

x^{2}-15x+c=(x-\sqrt{c})^{2}\\\\x^{2}-15x+c=x^{2}-2\cdot x\cdot\sqrt{c}+c\\\\15x=2\cdot x\cdot\sqrt{c}\\\\15=2\cdot\sqrt{c}\\\\\sqrt{c}=\frac{15}{2}\\\\c=[\frac{15}{2}]^{2}\\\\c=\frac{225}{4}

Thus, the value of <em>c</em> is \frac{225}{4}.

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The solution is listed below

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Answer:

b

Step-by-step explanation:

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