how to do systems of equations
Algebra

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i am failing math because of this unit. i need desperate help with the unit in general
to solve system of equations given such as y3x=5 and y+x=3 we first want to isolate a variable in this case will use y (NOW you want to keep it easy so isolate y from the second equation not the second one) so y=3x then we sub this equation into the second one whereever y appears because we know y=3x so now we get
3x3x=5 now you expand 4x=2 rearrange and isolate x and get x=1/2 now we solve for y
y+x=3 1/2+x=3 y=3.5
then we verify by plugging into the second equation
3.53(0.5)=5 3.5+1.5=5 5=5
now if you do it the other way such as x=3y when you plug it into the other equation you have to multiply out the 3 so that y3(3y)=5 y9+3y=5 4y=14 y=3.5
so you can isolate y or x and get the same answer.
Hope this helps if you need more just ask
in short
isolate a variable from one equation
sub it into the other equation then solve
take that and sub it into the first equation and solve
then verify your equations by plugging both variables (the numbers) in to the other equation
Here is a link to also help you: http://cstl.syr.edu/FIPSE/Algebra/Unit5/subst.htm
This helped a lot! i have a teacher that's very hard to understand and doesnt explain thngs very well but thios is perfect. Thank you!
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