I need help i dont understand

7nadin3 [17]

Las edades de cada uno de los integrantes del acertijo son:

Luisa = 3 años
Juan = 6 años
Carmen = 8 años

Cálculo por medio de ecuaciones.

Para identificar la edad de cada persona en el acertijo, se pueden crear ecuaciones con la información brindada, aunque, primero se deben asignar variables:

L = Edad de Luisa
J = Edad de Juan
C = Edad de Carmen

Teniendo estas variables se procede a crear las ecuaciones, la primera parte del ejercicio dice que "Luisa es 3 años más joven que su hermano Juan", entonces la ecuación podría ser:

1. J = L + 3

La segunda parte dice que "su hermana Carmen es 2 años mayor que Juan", entonces:

2. C = J + 2

Y la tercera parte menciona que "Juan tiene el doble de edad que Luisa", por lo tanto:

3. J = 2L

Se realiza el método de reducción con la primera y la tercera ecuación, para calcular el valor de L:

1. J = L + 3 (Se multiplica por (-1) puesto que la variable que se busca reducir es J)
3. J = 2L

Entonces se calcula:

- J = - L - 3
J = 2L

0 = L - 3 (El número 3 que está restando se pasa a sumar al otro lado de la igualdad)
3 = L
L = 3

Teniendo el valor de L, se calcula el valor de J con la tercera ecuación:

J = 2L
J = 2 * 3
J = 6

Y con el valor de J, se calcula el valor de C con la segunda ecuación:

C = J + 2
C = 6 + 2
C = 8

De esta forma, se calcula que las edades de Luisa, Juan y Carmen son: 3 años, 6 años y 8 años respectivamente.

Más información:

brainly.com/question/1225667?referrer=searchResults

3 0

3 years ago

Factor this polynomial completely. x^2 + 3x -18

ArbitrLikvidat [17]

Answer:

$(x+6)(x-3)$

Step-by-step explanation:

$x^2+3x+18$

$x^2+6x-3x-18$

$x(x+6)-3(x+6)$

$(x+6)(x-3)$

8 0

3 years ago

steve made a mistake in writing a two step equation. Instead of multiplying by 3 and adding 7, he multiplied by 7 and added 3 to

rjkz [21]

Answer:

The correct answer of the problem is 1.

Step-by-step explanation:

Let the original number on which the wrong procedure is applied is x.

Now, Steve multiplied by 7 and then added 3 to get the answer of - 11.

So, 7x + 3 = - 11

⇒ 7x = - 14

⇒ x = - 2

Now, the correct step to get the answer is multiplying by 3 and adding 7.

Hence, the correct answer of the problem is (- 2) × 3 + 7 = - 6 + 7 = 1 (Answer)

8 0

4 years ago

In an arithmetic sequence, a_17 = -40 and a_28 = -73. Please explain how to use this information to write a recursive formula fo

Vinvika [58]

An arithmetic sequence

$a_1,a_2,a_3,\ldots,a_n,\ldots$

is one in which consecutive terms of the sequence differ by a fixed number, call it d. This means that, given the first term $a_1$ , we can build the sequence by simply adding d :

$a_2=a_1+d$

$a_3=a_2+d$

$a_4=a_3+d$

and so on, the general pattern governed by the recursive rule,

$a_n=a_{n-1}+d$

We can exploit this rule in order to write any term of the sequence in terms of the first one. For example,

$a_3=a_2+d=(a_1+d)+d=a_1+2d$

$a_4=a_3+d=(a_1+2d)+d=a_1+3d$

and so on up to

$a_n=a_1+(n-1)d$

In this case, we're not given the first term right away, but the 17th. But this isn't a problem; we can use the same exploit to get

$a_{18}=a_{17}+d$

$a_{19}=a_{17}+2d$

$a_{20}=a_{17}+3d$

and so on, up to the next term we know,

$a_{28}=a_{17}+11d=-40+11d$

(Notice how the subscript of a on the right and the coefficient of d add up to the subscript of a on the left.)

The 28th term is -73, so we can solve for d :

$-73=-40+11d\implies -33=11d\implies d=-3$

To get the first term of the sequence, we use the rule found above and either of the known values of the sequence. For instance,

$a_{17}=a_1+16d\implies-40=a_1-16\cdot3\implies a_1=8$

Then the recursive rule for this particular sequence is

$\begin{cases}a_1=8\\a_n=a_{n-1}-3&\text{for }n>1\end{cases}$

7 0

3 years ago

How do I make a graph for this?

12345 [234]

To calculate the slope of a line you need only two points from that line, (x1, y1) and (x2, y2).

The equation used to calculate the slope from two points is:On a graph, this can be represented as:

There are three steps in calculating the slope of a straight line when you are not given its equation.

Step One: Identify two points on the line.Step Two: Select one to be (x1, y1) and the other to be (x2, y2).Step Three: Use the slope equation to calculate slope.

Take a moment to work through an example where we are given two points.

Example

Let's say that points (15, 8) and (10, 7) are on a straight line. What is the slope of this line?

Step One: Identify two points on the line.In this example we are given two points, (15, 8) and (10, 7), on a straight line.Step Two: Select one to be (x1, y1) and the other to be (x2, y2).It doesn't matter which we choose, so let's take (15, 8) to be (x2, y2). Let's take the point (10, 7) to be the point (x1, y1).Step Three: Use the equation to calculate slope.Once we've completed step 2, we are ready to calculate the slope using the equation for a slope:We said that it really doesn't matter which point we choose as (x1, y1) and the which to be (x2, y2). Let's show that this is true. Take the same two points (15, 8) and (10, 7), but this time we will calculate the slope using (15, 8) as (x1, y1) and (10, 7) as the point (x2, y2). Then substitute these into the equation for slope:We get the same answer as before!

Often you will not be given the two points, but will need to identify two points from a graph. In this case the process is the same, the first step being to identify the points from the graph. Below is an example that begins with a graph.

Example

What is the slope of the line given in the graph?
The slope of this line is 2.

[detailed solution to example]

Now, take a moment to compare the two lines which are on the same graph.

Notice that the line with the greater slope is the steeper of the two. The greater the slope, the steeper the line. Keep in mind, you can only make this comparison between lines on a graph if: (1) both lines are drawn on the same set of axes, or (2) lines are drawn on different graphs (i.e., using different sets of axes) where both graphs have the same scale.

5 0

4 years ago