All categories

3 years ago

How to substitute x=-2 and x=5 into 2x^2+6-20=0 to check my work

1 answer:

4 0

First answer (x=-2)
...
(2)[(-2)^2]+6-20
2(4)+6-20
8+6-20
14-20
-6 (answer)

Second answer (x=5)
...
(2)[(-5)^2]+6-20
2(25)+6-20
50+6-20
56-20
36 (answer)
Hope this helps!

You might be interested in

Triangles Q R S and X Y Z are shown. Angles Q S R and X Z Y are right angles. Angles Q R S and X Y Z are congruent. The length o

kumpel [21]

Answer:

Three-fourths

Step-by-step explanation:

see the attached figure to better understand the problem

we know that

∠QSR≅∠XZY ---> given problem

∠QRS≅∠XYZ ---> given problem

△QRS ~ △XYZ ----> by AA Similarity theorem

Remember that, if two triangles are similar, then the ratio of its corresponding sides is proportional and its corresponding angles are congruent

That means

$\frac{QS}{XZ}=\frac{QR}{XY}=\frac{RS}{YZ}$

∠Q≅∠X

∠R≅∠Y

∠S≅∠Z

In the right triangle XYZ

Find the tangent of angle X

$tan(X)=\frac{YZ}{XZ}$ ---> opposite side angle X divided by adjacent side angle X

substitute the given values

$tan(X)=\frac{9}{12}$

Simplify

$tan(X)=\frac{3}{4}$

Remember that

∠Q≅∠X

$tan(Q)=tan(X)$

therefore

$tan(Q)=\frac{3}{4}$ ---->Three-fourths

7 0

3 years ago

Read 2 more answers

100 POINTS!!! Brainliest if correct, I report if the answer is absurd. Don’t answer if don’t know.

Lena [83]

Answer: D

Step-by-step explanation:

To find the perimeter of the square, you want to first find the length of each side. Since the figure is a square, we know that each side is equal to each other. We can set the expressions equal to each other to find x.

$\frac{3}{4}x-1=\frac{1}{2}x+7$ [subtract both sides by 1/2x]

$\frac{1}{4}x-1=7$ [add both sides by 1]

$\frac{1}{4}x=8$ [multiply both sides by 4]

$x=32$

Now that we know x, we can plug it into each expression to find teh length of each side.

$\frac{3}{4}(32)-1$ [multiply]

$24-1$ [subtract]

$23$

Now that we know each side is equal to 23, we can add all the sides together to find the perimeter.

23+23+23+23=92 or 23×4=92

Since we know that the perimeter is 92 units, the answer is D.

3 0

4 years ago

Read 2 more answers

Imaginá que tenés 125 dados cúbicos del mismo tamaño ¿Cuantos dados de altura tiene el cubo de mayor tamaño que podés armar apil

kumpel [21]

Answer:

(i) Debemos apilar 5 dados para construir el cubo de mayor tamaño.

(ii) Se necesita 121 dados cuadrados para formar el cuadrado con la mayor cantidad de dados posibles, quedando 4 dados sobrantes.

Step-by-step explanation:

(i) Sabemos por la Geometría Euclídea del Espacio que un cubo es un sólido regular con 6 caras cuadradas y longitudes iguales. Cada dado tiene un volumen de 1 dado cúbico y 125 dados dan un volumen total de 125 dados cúbicos.

El volumen de un cubo está dado por la siguiente fórmula:

$V = L^{3}$

Donde:

$L$ - Longitud de la arista, medida en dados.

$V$ - Volumen del cubo, medido en dados cúbicos.

Ahora, necesitamos despejar la longitud de la arista para calcular la altura máxima posible:

$L = \sqrt[3]{V}$

Dado que $V = 125\,dados^{3}$ , encontramos que la altura del cubo de mayor tamaño sería:

$L =\sqrt[3]{125\,dados^{3}}$

$L = 5\,dados$

Debemos apilar 5 dados para construir el cubo de mayor tamaño.

(ii) El área cuadrada formada por cubos está determinada por la siguiente fórmula:

$A = L^{2}$

Donde:

$L$ - Longitud de arista, medida en dados.

$A$ - Área, medida en dados cuadrados.

Puesto que la longitud de arista se basa en un conjunto discreto, esto es, el número de dados disponibles, debemos encontrar el valor máximo de $L$ tal que no supere 125 y de un área entera. Es decir:

$L \leq 125\,dados$

Si cada cubo tiene un área de 1 dado cuadrado, entonces un cuadrado conformado por 125 dados tiene un área total de 125 dados cuadrados. Entonces:

$L^{2}< 125\,dados^{2}$

Esto nos lleva a decir que:

$L < 11.180\,dados$

Entonces, la longitud máxima del cuadrado con la mayor cantidad de cubos posible es de 11 dados. El número total requerido de cubos es el cuadrado de esa cifra, es decir:

$n = (11\,dados)^{2}$

$n = 121\,dados$

Se necesita 121 dados cuadrados para formar el cuadrado con la mayor cantidad de dados posibles, quedando 4 dados sobrantes.

4 0

3 years ago

Of the 250 students at Moreland middle school, 80% ride the bus to school. Monica wants to know the number of students that ride

LekaFEV [45]

You would put 80 x
—- = ——
250 100

So those are fractions^
The first thing you do here is cross-multiply. (It doesn’t matter which sides you multiply together first)
So 250 times x= 250x
Then cross multiply 80 and 100 to get:
8,000
You now have ur new equation:
250x=8,000
The next thing you do here is divide both sides by 250, since 250 is the number with a variable in it (aka “x”)
You then get:
32 students as you’re final answer.
I hope that helped you understand !

7 0

3 years ago

PLS HELP WITH THIS ANSWER!!! AND ASAP PLS DONT ANSWER WRONG!!

VMariaS [17]

I got you- The answer is (B. 4) hope this helps, if you need me to explain ask in the comments. Have a good day/night:)

5 0

3 years ago