solve system of linear equations by substitution -2x+9y=15
x+7=4 ​

Answer:

C

Step-by-step explanation:

Look at the attachment

Answer:

40

Step-by-step explanation:

You need to take 30%of 40 to figure it out.

Hope this helps.

Answer:

I think they are the range, the interquartile range. Tell me if if wrong!

Step-by-step explanation:

Answer:

1. The amount that was not spent is: 1080 soles

2. The answer is 5.

Step-by-step explanation:

Question 1. There are two situations:

If you spent 5/8 of the money then notice, that u did not spend 3/8.

If you spend 2/5 of the money, then you would have 72 more.

So think, this equation:

3/8x + 72 = 2/5x

2/5 of the money is the value for what you did not spend plus 72, the amount you would have, where x is the answer for the total of money.

72 = 2/5x - 3/8x

72 = 1/40x

x = 2880 soles

As you did not spend 3/8 of 2880, the answer is 1080 soles

Notice that if u spent 2/5 of 2880, you would have 1152 soles, so, the 1080 + 72, as the problem said.

Question 2.

We think letters for this excersise.

N = My born year

2020 (this year) - N = E (my age, now)

So N + 10 = when I get 10 years old

N + 20 = when I get 20 years old

N + 30 = when I get 30 years old

N + 40 = when I get 40 years old

The problem says:

(N+10) + (N+20) - (N+E) = 2020

((N+30)+E) - (N-40) = X  

So if 2020 - N = E, then notice that 2020 - E = N. Let's replace this in the equation form:

((2020-E)+10) + ((2020-E)+20) - ((2020-E)+E) = 2020

No minus in the first two terms, so we can break the ( )

2020-E+10 + 2020-E+20 - ((2020-E)+E) = 2020

We apply the distributive property for the second term

2020-E+10 + 2020-E+20 - 2020+E-E = 2020

We can cancel two E, and the 2020, so the new form will be:

2020 - 2E + 30 = 2020

We can also cancel the 2020, so if we reorder the equation, we have:

-2E = -30

E = 15 That's my age, so my born's year is 2020 - 15 = 2005 (N)

Look:

(2005 + 10) + (2005+20) - (2005+15) = 2020

So now, the last part

((2005+30)+15) - (2005+40) = 5

Answer:

[tex]\frac{9}{4}[/tex] or [tex]2\frac{1}{4}[/tex]

Step-by-step explanation:

If Mr. Tuyen used 3/4 of a tank in a week, then in three weeks, he would use that same amount times three.

So:  [tex]\frac{3}{4}[/tex] x 3 = [tex]\frac{9}{4}[/tex]

Hope this helps :)

Answer: (x +4)(x - 4)

Step-by-step explanation: Since x² - 16 represents the difference of two squares, it can be factored as the product of two binomials, one that has a plus in it and one that has a minus in it.

The first position in each binomial is filled by

the factors of x² that are the same, x times x.

The second position in each binomial is filled

by the factors of 16 that are the same, 4 times 4.

The answer therefore is (x + 4)(x - 4).

Answer: The correct answer is A

Step-by-step explanation:

Answer:

download my math scanner it's the only math app I know actually works

Answer:

irrational

Step-by-step explanation:

because an irrational number goes on forever so no matter what number is added to it it will always be irrational.

Answer:

Rational

Step-by-step explanation:

Answer:

There are 24 students in the class.

Step-by-step explanation:

If four students are 1/6 of the class, you need to multiply 4 times 6 to get 24.

Answer:

7:33 p.m.

Step-by-step explanation:

Para resolver este problema, necesitamos encontrar el mínimo común múltiplo de los intervalos en los cuales se encienden los faros. Para eso necesitamos primero convertir el tiempo que tarda el tercer faro en segundos. Sabemos que cada minuto tiene 60 segundos en total, así que el tercer faro se encenderá cada 60 segundos.

Luego de tener todos los tiempos en segundos, procedemos a escribirlos en una tabla como la siguiente:

12   18   60

La idea es buscar los números primos que todos tengan en común y dividirlos todos entre dichos números primos hasta que ya no podamos dividirlos más, por ejemplo, estos números se pueden dividir todos dentro de 2 así que hacemos eso:

12  18   60  |  2

6   9    30  |  2   dos de estos números nuevos pueden ser dividos entre dos también, así que hacemos justo eso.

12  18   60  |  2

6   9    30  |  2

3   9    15   | 3   ahora todos pueden ser divididos entre 3, así que obtenemos:

12  18   60  |  2

6   9    30  |  2

3   9    15   | 3

1    3     5   |  3    uno de estos números se puede dividir entre 3 y obtenemos.

12  18   60  |  2

6   9    30  |  2

3   9    15   | 3

1    3     5   |  3

1    1      5   |  5  y finalmente dividimos entre 5 para obtener:

12  18   60  |  2

6   9    30  |  2

3   9    15   | 3

1    3     5   |  3

1    1       5   |  5

1    1       1    

luego que terminamos la tabla tomamos todos los números que usamos para dividir y los multiplicamos entre si para obtener:

2*2*3*3*5=180s

los tres focos se volverán a prender luego de 180s. Si pasamos los 180s a minutos, tenemos que:

[tex]\frac{180}{60}=3min[/tex]

entonces lo único que tenemos que hacer es sumarle esos 3 minutos a la hora que nos dieron originalmente para obtener:

7:30 + 3 min = 7:33pm

la cual es nuestra respuesta.

Answer:

2. -1, -7, -19, -43, -91, -187,...

Step-by-step explanation:

[tex] \purple{ \bold{a_1 = - 1}}...(given) \\ a_n = 2a_{n - 1} - 5 \\ a_2 = 2a_{1} - 5 = 2( - 1) - 5 = - 2 - 5 = \\ \purple{ \bold{a_2 = - 7}} \\ \\ a_3 = 2a_{2} - 5 = 2( - 7) - 5 = - 14 - 5 \\ \purple{ \bold{a_3 = - 19}} \\ \\ a_4 = 2a_{3} - 5 = 2( - 19) - 5 = - 38 - 5 \\ \purple{ \bold{a_4 = - 43}}\\ \\ a_5 = 2a_{4} - 5 = 2( - 43) - 5 = - 86 - 5 \\ \purple{ \bold{ a_5 = - 91}}\\ \\ a_6 = 2a_{5} - 5 = 2( - 91) - 5 = - 182- 5 \\ \purple{ \bold{a_6 = - 187}}\\ [/tex]

Hence, first six terms of the given sequence are -1, -7, -19, -43, -91, -187,...

Answer:

39 homes

Step-by-step explanation:

The fraction of homes is 13/20

We are checking 60 homes

13/20 * 60 = 39

39 homes

Answer:

x = 4

y = 11

Step-by-step explanation:

You can make the equations 3x - 1 = 2x + 3

x = 4

y = 11

Answer:

(a) 300

(b)100

Step-by-step explanation:

(a) each figure is 100 student and there are 3 figures at Woodbridge so it's 3*100=300

(b) DuBois=3*100=300

Polk=4*100=400

400-300=100

the answer is 0.85

because 25 plus 60

is 85

Answer:

1099 inches

Step-by-step explanation:

We know that formula for volume of a cylinder is:

[tex]V=\pi r^2h[/tex]

[tex]V=\pi 5^2*14[/tex]

[tex]V=\pi 25*14[/tex]

[tex]V=\pi 350[/tex]

[tex]V=3.14*350[/tex]

[tex]V=1099[/tex]

Answer:

1099

Step-by-step explanation:

Answer:

infinitely many solutions

Step-by-step explanation:

Reduce the second equation by dividing all three terms by 3:  y + 1 = 2x.  Then compare this result to the first equation 2x - y = 1.  Noe that these two equations are identical.  Thus, the two lines coincide.  There are "infinitely many solutions."

The answer that I got was 7/7

Answer:

The slope of the line is 1

Step-by-step explanation:

the formula for slope is y2-y1 / x2-x1. The point (-4,2) could be labeled as x1 and y1, where x1 is -4 and y1 is 2 and the point (3,9) could be labeled as x2 and y2, where x2 is 3 and y2 is 9. So then the equation would be set up as the following: 9-2 / 3--4. Simplified, the equation equals 1, because when you subtract it comes out as 7/7.

Hope this helps :)

Answer:

[tex]\frac{1}{3}[/tex] chance.

Step-by-step explanation:

The only factors of 6 on a die is 1, 2, 3, and 6

The chance of getting 4 or 5 (not factors of 6) is [tex]\frac{2}{6} =\frac{1}{3}[/tex] chance.

(None of the options you gave is correct)

The probability of getting numbers which is not a factor of 6.

                          [tex]P(E)=\frac{2}{6}=\frac{1}{3}[/tex]

To understand more, check below explanation.

The numbers on die which is factors of 6 is,

                               1,2,3,6

So that, numbers on die which is not factor of 6 is, 4 and 5.

We have to find probability that  the score is not a factor of 6.

Total number of favorable outcomes = 2

Total outcomes = 6

Probability that  the score is not a factor of 6,

                          [tex]P(E)=\frac{2}{6}=\frac{1}{3}[/tex]

Learn more about the probability here:

https://brainly.com/question/24756209

Answer:

Surface Area  = 4928 ft^2

Step-by-step explanation:

Easy way -

First find the area of each face i.e.

56 * 20 =  1120

65 * 20 = 1300

33 * 20 = 660

2 * (1/2 * 56 * 33) = 1848

Total = 4928 ft^2

Answer:

-tan 20

Step-by-step explanation:

They have the same answer when typed in a calculator

Answer:

Read below

Step-by-step explanation:

I don't know your teacher's name but I know the answer to the other question.

Each additional mile will take a longer time of 2 minutes. Because the miles increase, the time would increase. If you think about it and you work as a pizza deliverer, the time should increase if the number of miles also increases. It's not magic.

Answer:

16.028 yards

Step-by-step explanation:

1 inch=0.0833333 foot

24 inches=0.0833333×24

=1.9999992 foot

The mirror is square shaped and each side is 24 inches

If each 24 inches=1.9999992 foot

Then,

4 sides of 24 inches=1.9999992×24

=47.9999808 foot

Maria has 1 foot of trim left

Total Length of trim when she started=47.9999808+0.0833333

=48.0833141 foot

=16.02777136667 yards

Approximately,

16.028 yards

Answer:

The cost of parking in the garage for 75 minutes is 4.875.

Step-by-step explanation:

The costs of parking h hours is given by the following function:

[tex]f(h) = 4.5 + 1.5(h-1)[/tex]

Cost of parking 75 minutes.

1 hour is 60 minutes. How many hours are 75 minutes?

1h - 60 min

xh - 75 min

[tex]60x = 75[/tex]

[tex]x = \frac{75}{60}[/tex]

[tex]x = 1.25[/tex]

75 minutes is 1.25 hours. So we have to find f(1.25).

[tex]f(1.25) = 4.5 + 1.5*(1.25-1) = 4.875[/tex]

The cost of parking in the garage for 75 minutes is 4.875.

Answer:

2) Only solar because u are near the moon lool

3) i think the same

1-4)There is, however, one side of the moon that never faces Earth head-on. The moon completes a full, 360-degree orbit around our planet every 27.32 days . That's about as long as it takes the moon to finish a single rotation on its own axis. Taken together, those two factors explain why only one side of the moon is ever oriented toward us and about 41 percent of the lunar surface is never visible to Earth-bound stargazer.

Eevery lunar day lasts for 29.5 Earth day

Answer:

A person

Step-by-step explanation:

I have heard this riddle multiple times, it is very well known and ( in my opinion ) very intriguing;

If we are considering the 4 legs in the morning, we can assume it to be a baby crawling on all 4's. 2 legs in the afternoon represents a more elderly person, a young child or adult on their 2 legs, and 3 in the night models an elderly person, using a walking stick as their " leg "

Answer; In other words, a person has 4 legs in the morning, 2 in the afternoon, and 3 at night

A human is one who has  4 legs in the morning, 2 in the afternoon, and 3 at night.

What is a riddle?

A statement, inquiry, or phrase with a hidden or double sense that is presented as a problem to be answered is called a riddle. A riddle often consists of a topic or a statement with numerous interpretations that must be resolved. Riddles can be humorous brain teasers or wanted-to-think puzzles. It is similar to working to remedy a riddle.

Morning represents a baby. A baby crawling in the morning has four legs and hands included.

An adult represent afternoon walks with two legs and they are the one who have to sand on their own.

An elderly person representing night who walks with the aid of a cane or walking stick is known as "3 legs in the evening." as they might have trouble while walking.

Learn more about riddle, Here:

https://brainly.com/question/478260

#SPJ2

Answer:

xx vrs. xy chromosomes in their genetics