x - 3y = 4
2x + y = 8
To solve this system using elimination, multiply the entire top equation by -2.
-2(x - 3y = 4)
-2x + 3y = -8
Now add the two equations together.
-2x + 3y = -8
2x + y = 8
+___________
0 + 4y = 0
y = 0
Substitute 0 for y into either of the original equations.
x - 3y = 4
x - 3(0) = 4
x - 0 = 4
x = 4
Lastly, substitute both values for x and y into both original equations to check work.
x - 3y = 4
4 - 3(0) = 4
4 - 0 = 4
4 = 4
2x + y = 8
2(4) + 0 = 8
8 + 0 = 8
8 = 8
Answer:
y = 0