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:
There are approximately 171 families in the sample.
Step-by-step explanation:
Percentile meaning:
When a value V is said to be in the xth percentile of a set, x% of the values in the set are lower than V and (100-x)% of the values in the set are higher than V.
Twenty-four of the families in the sample turned on the television for 23 hours or less for the week. The 14th percentile of the data is 23 hours.
This means that 24 is 14% of the total number of families.
Approximately how many families are in the sample?
Using a rule of three.
24 - 0.14
x - 1
0.14x = 24
x = 24/0.14
x = 171.4
Rounding to the nearest integer
There are approximately 171 families in the sample.
Answer:
This is because to square a number just means to multiply it by itself. For example, (-2) squared is (-2)(-2) = 4. Note that this is positive because when you multiply two negative numbers you get a positive result.
89-131=-42 the answer is k=-131
It's a parallelogram so if one angle is 90 degrees they all will be because of transverse angles and all that good stuff.
So we're given the diagonal of a rectangle and one side and we're asked to find the other. The diagonal of a rectangle is the hypotenuse of the right triangle whose legs are the sides of the rectangle. So this is a Pythagorean Theorem question in disguise:




Answer: 140 cm
I don't recall seeing this Pythagorean Triple before.