The problem already gives you what "y" equals.
Y = x + 1.75
So, since we know what "y" is, we can SUBSTITUTE that in for the "y" in the second equation and solve for X.
4x - 2( x + 1.75) = 4
4x - 2x - 3.5 = 4
2x -3.5 = 4
2x = 7.5
X = 3.75
Now that you have X, plug it back into one of the original given equations. It does not matter which one.
Y = 3.75 + 1.75
Y = 5.5
Answer: (X, Y) = (3.75, 5.5)