Answer:
El valor de <em>x</em> es igual a 20 o <em>x</em> = 20.
Step-by-step explanation:
Lo primero que se debe saber es que <em>dos ángulos complementarios suman un ángulo recto o 90º</em>.
Supongamos que el valor de un ángulo
y un ángulo
valen:
[1]
[2]
Como la suma de
[3]
Entonces

Sumamos los factores comunes entre si:

Para la primera expresión debemos recordar que se suman sólo los coeficientes. Así:


Para despejar la incógnita <em>x</em>, debemos tener en cuenta que <em>una igualdad no se altera si se suma, se resta, se multiplica o divide un mismo valor a cada lado de ella</em>. Por esta razón, para despejar 3x, lo primero que podemos hacer es sumar -30 a cada lado de la expresión (lo que es igual a restar 30 a cada lado de la misma). Así tenemos:



Ahora dividimos cada miembro de la igualdad entre 3 (o multiplicamos cada lado de la igualdad por
):
Como sabemos que:

Entonces:



De esta manera, el valor de <em>x</em> es igual a 20 o x = 20.
Lo anterior lo podemos comprobar considerando las ecuaciones [1], [2] y [3]. Así tenemos que:
[1]
Sustituimos x por el valor de 20:

[2]
Hacemos lo mismo para [2]:


De esta manera:
[3]

Answer:
And we can find this probability with this difference:
And in order to find these probabilities we can use tables for the normal standard distribution, excel or a calculator.
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the number of passengers who arrive at the platform of a population, and for this case we know the following info
Where
and
We are interested on this probability
For this case we can assume that the random variable is normally distributed.
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability with this difference:
And in order to find these probabilities we can use tables for the normal standard distribution, excel or a calculator.
Answer:
69
Step-by-step explanation:
m1 = 180 - (180 - 39 - 30) = 180 - 111 = 69
Answer:
a2
Step-by-step explanation:
you're using the pythagorean theorem
Answer:

Step-by-step explanation:
Rewrite the system of equations as:

Subtract the second equation from the first to isolate
:

Plug in
into any of the equations above and solve for
:

Verify that the solution pair
works 
Therefore, the solution to this system of equations is:
