<img src="https://tex.z-dn.net/?f=%285-2i%29%5E%7B2%7D" id="TexFormula1" title="(5-2i)^{2}" alt="(5-2i)^{2}" align="absmiddle" c

13 = -7 + 9x - 5x<br> X =

brilliants [131]

Answer:

x = 5

Step-by-step explanation:

Given

13 = - 7 + 9x - 5x , that is

13 = - 7 + 4x ( add 7 to both sides )

20 = 4x ( divide both sides by 4 )

5 = x

3 0

3 years ago

A circle has center at –6 + 2i and a point on the circle at 4 + 26i. Which of the following points is also on the circle?

Alenkasestr [34]

Answer:
–16 – 22i
Step-by-step explanation:
The radius of the circle = 4 + 26i - (-6 + 2i)
= 10 + 24i.
The radius will be the absolute values of this |10 + 24i|.

If a point is on the circle then it's distance from the centre must be 10+ 24i.
-19 + 15i - (-6 + 2i) = -13 - 13i , so this is not on the circle.
-16 - 22i - (-6 + 2i) = -10 - 24i = |10 + 24i| , so this is on the circle.
5 + 16i - (-6 + 2i) = 11 + 14i , so this is not on the circle.
20 - 24i - (-6 + 2i) = 26 - 26i. so this is not on the circle.

3 0

2 years ago

How long does it take the ball to hit the ground when dropped from 50ft.?

bixtya [17]

I hope it's about 1.8 sec

4 0

3 years ago

A radioactive substance decreases in the amount of grams by one-third each year. If the starting amount of the

katovenus [111]

Answer:

The sequence is geometric. The recursive formula is $a_{n}=2/3a_{n-1}$

Step-by-step explanation:

In order to solve this problem, you have to calculate the amount of the substance left after the end of each year to obtain a sequence and then you have to determine if the sequence is arithmetic or geometric.

The substance decreases by one-third each year, therefore:

After 1 year:

$1452-\frac{1}{3}(1452)$

Using 1452 as a common factor and solving the fraction:

$1452(1-\frac{1}{3})=1452(\frac{2}{3})=968$

You can notice that in general, after each year the amount of grams is the initial amount of the year multiplied by 2/3

After 2 years:

$968(\frac{2}{3})=\frac{1936}{3}$

After 3 years:

$\frac{1936}{3}(\frac{2}{3})=\frac{3872}{9}$

The sequence is:

1452,968,1936/3,3872/9....

In order to determine if the sequence is geometric, you have to calculate the ratio of two consecutive terms and see if the ratio is the same for all two consecutive terms. The ratio is obtained by dividing a term by the previous term.

The sequence is arithmetic if the difference of two consecutive terms is the same for all two consecutive terms.

-Calculating the ratio:

For the first and second terms:

968/1452=2/3

For the second and third terms:

1936/3 ÷ 968 = 2/3

In conclussion, the sequence is geometric because the ratio is common.

The recursive formula of a geometric sequence is given by:

$a_{n}=ra_{n-1}$

where an is the nth term, r is the common ratio and an-1 is the previous term.

In this case, r=2/3

7 0

3 years ago

4. Your class is going to elect a President and Vice President. In how many ways can 2 people be elected if your class has 30 st

lina2011 [118]

Ok so all you have to do is

5 0

2 years ago

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