Solve the linear system using elimination.
3x-2y=3
-x+y=1

Question

Solve the linear system using elimination.
3x-2y=3
-x+y=1

solomonzelman · Answer

way 1:
Multiply the second equation times 3, and add the equations.

solomonzelman · Answer

way 2:
-x+y=1    --->    y=x+1       therefore,
3x-2y=3  --->   3x-2(x+1)=3

(substitution)

ineedhelpfast12 · Answer

so 3x-2y=3
-3x=3y=3

solomonzelman · Answer

way 3:
multiply the second equation times -2 and add the equations.

solomonzelman · Answer

, you are going by way 1. ok

solomonzelman · Answer

check equation 2 please

ineedhelpfast12 · Answer

so y is 1.5?

solomonzelman · Answer

I don't think so

solomonzelman · Answer

can you please multiply the second equation times 3, and add the equations.

ineedhelpfast12 · Answer

3x-2y=3
-3x+3y=3

nincompoop · Answer

first we need to think why are we multiplying

ineedhelpfast12 · Answer

What do you mean?

nincompoop · Answer

why are you multiplying?

ineedhelpfast12 · Answer

thats the only way for the problem to work. If there is a negative and positive x or y that matches with the other, then the problem works out evenly

nincompoop · Answer

read the instruction
it says solve by elimination. 
Now what are you trying to eliminate?

ineedhelpfast12 · Answer

either the x or the y

nincompoop · Answer

good 
then how are you going to do that?

ineedhelpfast12 · Answer

by multiplying. I dont get the point you are trying to make

nincompoop · Answer

here is the point, if you knew right from the beginning what you need to do, why are you asking for help?

ineedhelpfast12 · Answer

because I am confused. If you are not going to help me, let me know. My internet shuts off soon, and I need this done by morning

nincompoop · Answer

I am not saying you cannot ask for help.  
so you are confused.
did you say what part of the solution process you are confused about?

ineedhelpfast12 · Answer

when I multiply and whatever, it cones out to be 2y=3

ineedhelpfast12 · Answer

why is that?

nincompoop · Answer

okay what were you trying to eliminate?

ineedhelpfast12 · Answer

the x

nincompoop · Answer

look at the x in the first equation and look at the x in the second equation 
what are their coefficients?

ineedhelpfast12 · Answer

huh?

nincompoop · Answer

what is the coefficient of x in the first equation
what is the coefficient of x in the second equation 

3x-2y=3   (equation1)
-x+y=1    (equation 2)

ineedhelpfast12 · Answer

whats a coefficient?

nincompoop · Answer

https://www.mathsisfun.com/definitions/coefficient.html

nincompoop · Answer

get it?

ineedhelpfast12 · Answer

so 3 for equation 1 and -1 for equation 2

nincompoop · Answer

great

ineedhelpfast12 · Answer

ok?

nincompoop · Answer

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