Question

2x-y=3, 7x-3y=12 substution method

Answer 1

@uri You aren't substituting there! :)

Answer 2

lol

Answer 3

would y be 3 as well?

Answer 4

@terenzreignz Am i wrong..

Answer 5

No... but the instructions *clearly* say 'use substitution'...

Answer 6

You eliminated there! :)

Answer 7

Ow.

Answer 8

Try it again @uri ^_^

Answer 9

Le doing accounting homework. :p

Answer 10

You and your excuses...
Anyway, @drea83
Your first step is to pick an equation (first one recommended) and isolate one of the variables (y recommended).

Answer 11

uri , can you write the question with system ?

Answer 12

Do you know system ?

Answer 13

When we have x & y use that

Answer 14

Look :!

Answer 15

Do this...
FOR SUBSTITUTION

STEP 1: Find the value of any variable in terms of the other variable in the first equation.

STEP 2:
2x-y=3
y = 2x - 3

STEP 3: NOW substitute this variable's value in the second equation.

STEP 4:
7x-3y=12
7x - 3(2x-3) = 12
7x - 6x + 9 = 12
Get x's value. ^_^ [Learnt that from @terenzreignz ]

STEP 5:
Put x's value in the first equation to get the y value. :D

Understood? :)

Answer 16

2x-3=y
and 7x-3y=12
so u get
y=2x-3 from the 1st eq..
replace its value in the 2nd eq..
so u get
12=7x-3(2x-3)
12=7x-6x+9
x = 3
put in the 1st eq u will get y = 3

Answer 17

@drea83
Understood this? :D

Answer 18

2x-y=3
7x-3y=12
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7 . (2x -y = 3)
2 . (7x-3y=12)
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And now we want find y s first so shold x1= -(x2)
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so we have :
14x - 7y =21
14x - 6y =24
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Now we should kill x s so reduse them :
but we dont have :
x1= -(x2)
so do it by (-1)
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-1 .( 14x - 7y =21)

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so we have :
-14x + 7y =-21
14x-6y=+12
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then reduse them from them !
-14x+7y =-21

14x -6y =12
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y =-9
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Y = -9
Now can you find X ?
Do you under stand ?