Part A) -x + y = 3
y = 3 + x
Now, substitute this value into 2nd equation,
2x + y = 6
2x +3 + x = 6
3x = 6 - 3
x = 3/3
x = 1
Now, substitute this value into 1st equation,
y = 3 + x
y = 3+1 = 4
In short, Your Answer would be: x = 1, & y = 4
Part B) Substitute both values in 1st equation:
-1 + 4 = 3
3 = 3
As, L.H.S = R.H.S our coordinates are correct [ Verified ]
Hope this helps!