Solve the system of equations using the Elimination Method?

A

AK23

New member
3x-y=4
6x-2y=1

I'm usually really good at these types of problems but I seem to be having trouble with this one...
Help would be much appreciated.
 
elimination method means you want to get rid of something... in this case, you want to get rid of one of the variables so you can solve the other one.

pick one you want to keep (solve) .. then multiply the equation by the OPPOSITE sign so when you add, you will cancel each of them out.

for ex: you have 3x - y = 4 and 6x - 2y = 1.
say you want to get rid of the x. you have 3x and 6x. in order for them to cancel out, they have to have opposite sings AND the same value. so if you have -6 and 6 when you add them, you'll cancel them out.
in order to make 3x into -6x, you have to multiply by -2.

so you multiply your ENTIRE equation by -2: -2 ( 3x - y = 4) --> -6x +2y = -8

now you have
-6x +2y = -8 and
6x - 2y = 1

then you add them: you get 0x + 0y = -7,

but 0 =?=7, that's not possible, so this system has no solutions.

good luck
 
3x - y = 4 ==> 1
6x - 2y = 1 ==> 2

For equation 1, times everything by 2
so it becomes....
6x - 2y= 8 ==>1
6x -2y = 1 ==>2

Eqn 1 take away eqn 2
6x - 6x -2y - - 2y = 8 - 1
.......which can't be right as you're left with 0.... on the left hand side.
Recheck your question, there must be something with the minuses....or this question won't make sense.
 
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