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4 years ago

Solve the system by the elimination method. Check your work. x - 3y = 0 3y - 6 = 2x

Mathematics

2 answers:

Leto [7]4 years ago

6 0

X - 3y=0
3y - 6 =2x
__________
x - 3y=0 ........(1)
-2x + 3y=6 ........(2)
__________
-x = 6 ==》x = -6 .........(3) subst. in (2)

-2 (-6) + 3y = 6 ==》3y= -6 ==》y = -2

Romashka [77]4 years ago

3 0

Answer:(-6,-2)

Explanation:
The elimination method calls for two variables that cancel each other out.
In this circumstance, you already have 3y and -3y.

First, make the orders of the equations the same. I got the x's to the same side on each equation.
This left me with:
x=3y 2x=3y-6.
Now, subtract the first equation from the second one to get x=-6.
That's the first part of the solution. For the y, you can just plug x into one of the equations and solve. I'll use the first one.
-6-3y=0.
Now get the ys to one side: -6=3y. Divide both sides by 3 to get y= -2.
Now that you have an x and a y coordinate, your solution is (-6,-2).

To check: plug both values in for their variables into each equation.
3(-2)-6=2(-6) solve to get... -12=-12, which is true, meaning the solution works for that equation.

-6-3(-2)=0 solve to get... 0=0. The solution works for both equations.

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PLZ HELP

lana [24]

Answer:

Part A:

To find the total length of the two sides you want to add them together:

(3x^2-2x-1)+(9x+2x^2-2)= you want to combine all like terms

3x^2+2x^2=5x^2, you add your coefficients and keep the exponents the same

-2x+9x=7x, you would combine like terms

-1-2=-3, you would subtract according to Keep, Change, Change

You now have:

5x^2+7x-3= Sides A+B

5x^2+7x-3

Part B:

To find the length of the third side you want to take the perimeter of the triangle and subtract it from our answer in part A

(5x^3+4x^2-x-3)-(5x^2+7x-3)

When subtraction polynomials we want to change the subtraction sign to addition and change the signs of the other number to the opposite sign to prevent making mistakes from subtraction, so you're new equation will look like this:

(5x^3+4x^2-x-3)+(-5x^2-7x+3)

Now we add all like terms again

5x^3, doesn't combine with any others so we leave it the same

4x^2-5x^2=-x^2, subtract them but remember to keep the exponents the same

-x-7x=-8x, again subtract terms but keep variable

-3+3=0, they cancel out so we don't have to worry about putting anything for this one

So now we are left with

5x^3-x^2-8x as our length for the third side

Third side equals 5x^3-x^2-8x

Part C:

For part A we added to get the total of sides B and A

For part B we subtracted the total perimeter from the total lengths of B and A, to figure out what C equals

Hope this helps ;)

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3 years ago

A plot of land is in the shape of a triangle. If one side is x meters, a second side (5x−3) meters, and a third side is ( 7x −

liubo4ka [24]

Given, the plot is in the shape of triangle.

First side = x meter

Second side = ( 5x-3 )meters

Third side = ( 7x-6 ) meters

Perimeter of triangle is equal to the sum of all the three sides.

Perimeter = $x + (5x-3) + (7x-6)$

Combine like terms by adding all the x terms together and all the constant terms together.

Perimeter = $(x+5x+7x) + ( -3 -6 )$

Perimeter = $13x - 9$ feet ... Answer

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3 years ago

A student's grade for the four quarters are 95, 83, 91, and 85. What does the student need to earn on the final exam to have an

gulaghasi [49]

Answer:

The least score the student can get is 71 to get an overall B average at the end of the year.

Step-by-step explanation:

Let the score she needs to get be = x

We now have to take the mean of all the five subjects <em>(including x)</em> and equate it to the least score she can have to get a B grade.

Let us take the least score the student needs to get a B grade to be 85

Mean of all 5 scores =

$\frac{95+83+91+85+x}{5}=85$

$\frac{354+x}{5} =85$

$354+x = 425$

$x = 71$

The least score the student can get is 71 to get an overall B average at the end of the year.

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3 years ago

I'LL CHOOSE A BRAINLIEST PERSON!!!

Tema [17]

It is D. After realizing the inequality to y>1, you can find D. To get y>1, you can see that there is a dotted line so there is no equal to and then you find that all y values are greater than 1 so we figure out it is D!

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3 years ago

Read 2 more answers

Can someone help me with these two questions?

fenix001 [56]

Answer:

17) A(-1,1) B(-1,4) C(5,1)

18) (From origin moving rightwards)

A(0,0) B(a, 0) C(a,a) D(0,a)

Step-by-step explanation:

17) You just count the steps, how many steps left, right, up, or down

18) The first point is at the origin, so 0,0

The second point that lies on the x axis is (a,0) as it is a distance from the origin, 0 because it's on the x-axis.

The third point is (a,a) because it is a distance to the right of the origin AND a distance upwards from the x axis.

The fourth point (0,a) because it is on the vertical line (0) and is a distance above the origin.

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3 years ago