Question

Can someone explain how I would do this?

Determine the value of y for the system of equations.

x − 3y = 4
2x + y = 8

Answer 1

you can do this by elimination
first multiply the first equation by - 1
then adding will eliminate x
solve for y
then plug this value of y back into the origintl equation ( first one will do) so you can solve for x

Answer 2

x - 3y = 4 --->(-2)
2x + y = 8
-----------
-2x + 3y = -8 (result of multiplying by -2)
2x + y = 8
-----------add
4y = 0
y = 0

now sub 0 in for y in either equation
2x + y = 8
2x + 0 = 8
2x = 8
x = 4

check..
x - 3y = 4
4 - 3(0) = 4
4 - 0 = 4
4 = 4 (correct)

x = 4 and y = 0

Answer 3

* correction multiply by -2 (!!!!!)

Answer 4

Thanks so much!! @texaschic101 @cwrw238

Answer 5

yw

Answer 6

do you have any questions at all ?

Answer 7

No I understood what you wrote @texaschic101

Answer 8

good to hear :)