3x - 2y = 18 and 5x - 4y = 28. Use the elimination method to solve this linear equation.?

Question

How do you use the elimination method? I don't understand it...

Answer 1

3x - 2y = 18;

Hence,
6x - 4y = 36;
4y = 6x - 36;
y = (6x - 36)/4

Using the elimination method,

5x - 4y = 28
5x - 4{(6x - 36)/4} = 28
5x - 6x + 36 = 28
-x = 28 - 36

Therefore:-
x = 8
y = 3

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I've decided to be kind here and to help you out

Answer 2

in using elimination method, we would want to eliminate either the terms containing x or the terms containing y.

in order to eliminate the said terms, their coefficients (the number before the letters) should be the same.

in your equations if we want to eliminate the y terms, the two equations should have the same coefficients. to do this, multiply the 1st equation by 2. and the equation would be 6x-4y=36. see, they are now both 4y. ^_^

6x - 4y = 36
5x - 4y = 28
we could add or subtract the 2 equations. but think first what you will do to have an answer of zero. if we add: -4y+(-4y)=-8y , if we subtract -4y-(-4y)=-4y+4y=0. therefore, we shall subtract.

(6x - 4y = 36)
- (5x - 4y = 28)
----------------------
x + 0 = 8
x=8 ^_^

substitute this value to the first equation:
6(8)-4y=36
48-4y=36
48-36=4y
12=4y
y=3 ^_^


i really hope you understood...

Answer 3

3x - 2y = 18 .... (1)
5x - 4y = 28 ..... (2)

(1) * -2 -----> -6x + 4y = -36 ..... (3)

Add (3) and (2),

5x - 6x - 4y + 4y = 28 - 36
-x = -8
x = 8

Put x = 8 in (1),
24 - 2y = 18
-2y = -6
y = 3

x = 8, y = 3 is the solution

Answer 4

3x-2y=18
5x-4y=28

Hint: Think of a number when multiplied on one equation can make any variable eliminate using addition or subtraction..

Multiply -2 on the first equation to make -2y become +4y
-2(3x-2y)=18(-2)
5x-4y=28

-6x+4y= -36
5x-4y=28

Now... add the two equations
-6x+5x= -x
+4y+(-4y)= 0
-36+28= -8

Giving you this equation: -x = -8

x=8
Now that you have the value of x subtitute it to the any of the equation then find y

5x-4y=28
5(8)-4y=28
40-4y=28
-4y= -12
y=3

So the value of y is 3
and the value of x is 8

Answer 5

Multiply the first equation (all terms) by -2. Then add. That will give you x after some algebra.

Then plug x in to find y.

I see you have the rest of your hw posted as well?

Listen, it is utterly worthless to post every problem here. Either you understand it, or you don't. Either learn it (by getting help with ONE problem, or don't learn it by copying.

I promise you, you will fail your exams miserably if you don't get a handle on math.

Copying work does absolutely NO GOOD.

Answer 6

3x-2y =18 ----------1
5x-4y=28 -----------2

1st equation * 2 6x-4y=36 -----------3
3-2 x=8

x=8,y=3