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3 years ago

Algebra 1 solve by elimination 6x-3y=30 6x+y=18

2 answers:

4 0

Slimination

the teacher probably wants you to eliminate the x terms since there are an equal number of them

so multiply first equation by -1
-6x+3y=-30
add to second equation
6x-6x+3y+y=18-30
0x+4y=-12
4y=-12
divide by 4
y=-3
subsitute
6x+-3=18
add 3
6x=21
divide both sides by 6
x=21/6=7/2

x=7/2
y=-3

bonufazy [111]3 years ago

3 0

First, we need the coefficient of one of our variables to be the same.
In this case, it's already done for us. We have 6x in both equations.

Now, we just subtract the equations.
$\ \ 6x-3y=30\\\underline{-6x+y=18}\\\overline{} \ \ \ \ -\ 4y=12\\\overline{} \ \ \ \ \ \ \ \ \ \ y=-3$

Note that the subtraction distributes to each term of that equation.

(you can also do something similar by adding equations--as long as you get rid of of that variable...and if your coefficients aren't the same to begin with, just multiply both sides of one of those equations to get them equal.)

Now, we just use that y = -3 to find x.

$6x+y=18\\6x-3=18\\6x=21\\\boxed{x=3.5}$

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3 years ago

What is the value of the expression below when z=2 4z2-3z-4 please help

Phoenix [80]

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6 0

3 years ago

Una empresa elabora aceites de tres calidades distintas. Del primer aceite se elaboran 640 L, del segundo 800 L, y del tercero 4

Alecsey [184]

El mayor tamaño de los contenedores será de 160 litros.

Dado que una empresa elabora aceites de tres calidades distintas, y del primer aceite se elaboran 640 L, del segundo 800 L, y del tercero 480 L, si se quiere envasar el aceite en contenedores del mismo tamaño, sin mezclar los de distinto tipo, para determinar cuál será el mayor tamaño que puede tener el contenedor se debe realizar el siguiente cálculo, obteniendo el divisor mayor común de estos números:

Así, en tanto 480, 640 y 800 son divisibles por 80, resta determinar si también lo son por 160.
Entonces, dado que 480/160 es igual a 3, 640/160 es igual a 4 y 800/160 es igual a 5, el divisor mayor común de estos números es 160.
Por ende, el mayor tamaño de los contenedores será de 160 litros.

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7 0

3 years ago

Find the value of x urgent!! plz help me! will give the brainliest

Anarel [89]

Answer:

x = 2

Step-by-step explanation:

$\frac{1}{2} (x - 1) - \frac{1}{6} (x+1) = 0$

In an equation our aim is to find the value of what we are looking for as well as keeping the equation balanced. For example if we divided by 2 only from one side then the equation would change so it's an important rule to keep in mind when solving equations, that you need to keep both sides of the equation the same.

$\frac{1}{2} (x - 1) - \frac{1}{6} (x+1) = 0$

→ Expand the brackets

$\frac{1}{2} x- \frac{1}{2}-\frac{1}{6}x -\frac{1}{6} =0$

→ Multiply everything by 12 to make solving the equation easier

6x - 6 - 2x - 2 = 0

→ Simplify equation

4x - 8 = 0

→ Add 8 to both sides to isolate 4x

4x = 8

→ Divide by 4 on both sides to isolate x

x = 2

⇒ We can substitute x = 2 back into the equation to see if the solution is correct, if we get 0 on both sides then x = 2 is correct

$\frac{1}{2} (x - 1) - \frac{1}{6} (x+1) = 0$

⇒ Substitute in the values

$\frac{1}{2} (2-1)-\frac{1}{6} (2+1) = 0$

⇒ Simplify

$\frac{1}{2} (1)-\frac{1}{6} (3) = 0$

⇒ Simplify further

$\frac{1}{2} -\frac{1}{2} =0$

0 = 0

The solution x = 2 is correct

4 0

3 years ago

Prove the following theorem indirectly. We will give you a start.. . Prove that a triangle cannot have two right angles.. A tria

ladessa [460]

Suppose a triangle had two right angles.
The sum of all angles of any triangle is 180°.
The measure of a right angle is 90°.
By difference, the measure of the other angle can be determined.
Since the two angles have a measure of 90° each, then by difference, the measure of the third angle is 180° - (90° + 90°) = 0°.
If the angle is 0°, there would only be two sides.
A triangle has three sides.
Therefore, a triangle can't have two right angles.

7 0

3 years ago

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