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3 years ago

13

La diferencia entre dos números es 45.Si al doble del primero se le suma el segundo,se obtiene como resultado 120 ¿ Cuales son e

sos números ?

1 answer:

Makovka662 [10]3 years ago

5 0

Answer:y

Step-by-step explanation:

You might be interested in

Let $a$ and $b$ be nonzero real numbers such that

algol [13]

<h3>Answer: -7/2</h3>

=========================================================

Explanation:

Let's expand out (2 - 7i)(a + bi) using the FOIL rule

(2 - 7i)(a + bi) = 2a + 2bi - 7ai - 7bi^2

(2 - 7i)(a + bi) = 2a + 2bi - 7ai - 7b(-1)

(2 - 7i)(a + bi) = 2a + 2bi - 7ai + 7b

(2 - 7i)(a + bi) = (2a+7b) + (2bi-7ai)

(2 - 7i)(a + bi) = (2a+7b) + (2b-7a)i

We're told the result is purely imaginary. What this means is that the real part (2a+7b) is zero, while the imaginary part (2b-7a) is nonzero. If both are zero, then we have 0+0i = 0 which is purely real.

For example, the complex numbers 0-7i and 0+2i are purely imaginary.

Let's use the fact that 2a+7b must be zero to do the following steps:

2a+7b = 0

2a = -7b

a = -7b/2

a/b = -7/2 which is the final answer

We must check to see if 2b-7a is nonzero

2b - 7a = 2b - 7(-7b/2)

2b - 7a = 2b + 24.5b

2b - 7a = 26.5b

The result is nonzero if and only if b is nonzero. Luckily we're told b is nonzero at the top of the problem. So we don't have any worries that (2b-7a) is zero.

Therefore, (2a+7b) + (2b-7a)i will be purely imaginary with a/b = -7/2

------------------

A concrete example:

Let a = -14 and b = 4

a/b = -14/4 = -7/2

(2-7i)(a+bi) = (2-7i)(-14+4i) = 0 + 106i which is purely imaginary.

I'll let you do the steps in expanding that out using the FOIL rule.

4 0

1 year ago

Expand and simplify 4 ( y + 6 ) − 2 ( y − 2 )

elena-14-01-66 [18.8K]

[ Answer ]

$\boxed{2y \ + \ 28}$

[ Explanation ]

4(y + 6) - 2(y - 2)

[Expand] 4(y + 6): 4y + 24

4y + 24 - 2(y - 2)

[Expand] -2(y - 2): -2y + 4

4y + 24 - 2y + 4

[Simplify] 4y + 24 - 2y + 4: 2y + 28

= 2y + 28

$\boxed{[ \ Eclipsed \ ]}$

7 0

3 years ago

Read 2 more answers

Graph y = 4x + 2 where is it grqphed at

cestrela7 [59]

Starting point: (0, 2) and can go to (1, 6).
This shows the slope and y-intercept. Hope this helps.

5 0

3 years ago

A woman is looking for a biker square office. She finds at office twice the area of her current office. If the perimeter of her

MatroZZZ [7]

Answer:

968

Step-by-step explanation:

Current office length = 22

22 * 22 = 484

484 * 2 = 968

8 0

3 years ago

Read 2 more answers

Adam’s sister wants to watch her intake of fat per day. He estimates that the dinner will have 48 grams of fat. What percentage

navik [9.2K]

First things to take note of to have the correct answer:
1. Adam's sister is obviously a girl. Then when looking at the data we look at the "Women" column.
2. We are only looking at the fats data.

We are asked for the percentage given 48 grams of fat and the daily allowance on fat for women is 70 g. To solve we perform the operation:

$% = \frac{70-48}{70} * 100 = 31.42% ≈ 31%$

3 0

3 years ago