Explanation:
-4.5x -2y = -12.5 -------(1)
3.25x -y = -0.75 --------(2)
From (2) we can make y the subject of the relation
y = 0.75+3.25x -------(3)
Input 0.75+3.25x into y in (1)
-4.5x -2(0.75+3.25x) = -12.5
-4.5x -1.5- 6.5x = -12.5
-4.5x -6.5x -1.5 = -12.5
-11x = -12.5 +1.5
-11x = -11
x = 11/11
x = 1
If x = 1,substitute 1 into x in (3)
y = 0.75+3.25x
y = 0.75 +3.25(1)
y = 0.75 +3.25
y = 4
x = 1,y = 4