Simplify the expression. -5a + 3b + 8a

La suma de las edades de tres personas es 127años. La mayor tiene 30 años mas que la menor y la del intermedio 26 menos que la m

Over [174]

Answer:

La mayor tiene 61 años.

Step-by-step explanation:

Sea x,y,z la edad de la mayor, intermedio y la menor respectivamente.

Tenemos las siguientes ecuaciones:

$x+y+z=127$ (la suma de las edades es 127)

$x = z+30$ (la mayor tiene 30 años más que la menor)

La frase "y la del intermedio 26 menos que la menor" no tiene sentido, puesto que esto implicaría que la del intermedio es menor que la menor. Luego se asume que la frase ha de ser "y la del intermedio 26 menos que la mayor"

$x-26 = y$ (la del intermedio tiene 26 menos que la mayor).

La segunda ecuación se traduce a x-30 =z. Si reemplazamos todo en la primera ecuación obtenemos

$x+(x-26)+(x-30) = 127$

Obtenemos la ecuación

$3x-56 = 127$

Sumando 56 a ambos lados y dividiendo por 3, obtenemos

$x = \frac{127+56}{3} = 61$

Es decir la mayor tiene 61 años.

6 0

3 years ago

To which set of numbers does the number below belong?

Luba_88 [7]

Integers are whole numbers that can range from negative infinity to positive infinity. Irrational numbers are numbers with repeating ends and have decimals. Rational numbers on the other hand can be positive or negative which can be expressed as fractions. natural numbers are positive integers only. hence, -14/11 is a D. rational number

7 0

3 years ago

Read 2 more answers

What’s the volume of a cone with the height of 18 and base of 8

sergij07 [2.7K]

Answer:

Step-by-step explanation:

8 0

4 years ago

What is the equation of the circle with center (1, -1) that passes through the point (5, 7)?

Inessa [10]

Answer:

Equation of the circle =

80 = ( x - 1)^2 + (y + 1)^2

Step-by-step explanation:

Center = (1 , -1)

Point = ( 5 , 7)

Eqn of a circle is

r^2 = (x - h)^2 + (y - k)^2

We are not given the radius of the circle, fortunately we are provided the information that the circle contains a point ( 5, 7), so we use the above information to find r

Using the center (1, -1)

h - 1

k - -1

r^2 = (x - 1)^2 + ( y - -1)^2

r^2 = (x - 1)^2 + (y + 1)^2

With the point ( 5,7)

x = 5

y = 7

r^2 = ( 5 - 1)^2 + ( 7 + 1)^2

= 4^2 + 8^2

= 16 + 64

= 80

r^2 = 80

r = square root of 80

r = 8.94

The r = 8.94 , which means the equation of the circle is

80 = (x - 1)^2 + ( y + 1)^2

5 0

3 years ago

The Fish and Game Department stocked a lake with fish in the following proportions: 30% catfish, 15% bass, 40% bluegill, and 15%

vagabundo [1.1K]

Answer:

1) $\chi^2 =\frac{(112-150)^2}{150}+\frac{(95-75)^2}{75}+\frac{(210-200)^2}{200}+\frac{(83-75)^2}{75}=16.313$

2) $p_v =P(\chi^2_{3}>16.313)=0.000978$

And we got the same decision reject the null hypothesis at 5% of significance.

Step-by-step explanation:

Previous concepts

The Chi-Square test of independence is used "to determine if there is a significant relationship between two nominal (categorical) variables". And is defined with the following statistic:

$\chi^2 =\sum_{i=1}^n \frac{(O-E)^2}{E}$

Where O rpresent the observed values and E the expected values.

State the null and alternative hypothesis

Null hypothesis: The distribution is 30% catfish, 15% bass, 40% bluegill, and 15% pike

Alternative hypothesis: The distribution is NOT 30% catfish, 15% bass, 40% bluegill, and 15% pike

The observed values are given by the table given:

Catfish =112, BAss = 95, Bluegill=210, Pike=83

Calculate the expected values

In order to calculate the expected values we can use the following formula for each cell of the table

$E = \% Grand total$

$E_{Catfish}=500*0.3=150$

$E_{Bass}=500*0.15=75$

$E_{Bluegill}=500*0.4=200$

$E_{Pike}=500*0.15=75$

Part 1: Calculate the statistic

$\chi^2 =\frac{(112-150)^2}{150}+\frac{(95-75)^2}{75}+\frac{(210-200)^2}{200}+\frac{(83-75)^2}{75}=16.313$

$\chi^2 =16.313$

Calculate the critical value

First we need to calculate the degrees of freedom given by:

$df= (categories-1)=(4-1)= 3$

Since the confidence provided is 95% the significance would be $\alpha=1-0.95=0.05$ and we can find the critical value with the following excel code: "=CHISQ.INV(0.95,3)", and our critical value would be $\chi^2_{crit}=7.815$

We can calculate also the p value:

$p_v =P(\chi^2_{3}>16.313)=0.000978$

And we got the same decision reject the null hypothesis at 5% of significance.

5 0

3 years ago