Question

for what value of k, x is equal to 2 and Y is equal to -1 is a solution of X + 3 Y - K is equal to zero

Answer 1

x+3y-k=0
by substituting the values we get,
2+3(-1) - k=0
2+(-3) -k=0
-1 -k=0
-k=1
k=-1

Answer 2

Given that, x=2and y=-1
And, x+3y-k=0
put x=2, y=-1 in the given equation
2+3(-1)-k=0
2-3-k=0
-1-k=0
k=-1