Question

x + y = 3k
x - y = k

The solution of the system shown is _____.

Answer 1

x+y=3k
x-y=k
---------
2x 0 = 4k

x= 4k/2 = 2k

x=2k

x+y=3k
2k +y=3k

y = 3k-2k = k

y=k

x=2k
y=k

Answer 2

jhonny is using the "elimination by addition and subtraction method" here, first to find x, and then to find k.