the 2 equations are
-2x + y = -17 ---1)
3x + y = 23 ---2)
we need to have the same coefficient for one of the variables.
Already y variable has the coefficient of 1 for both equations so we can use the equations as it is.
2) - 1) subtract 1) from 2)
3x-(-2x) + y -y = 23-(-17)
5x = 40
x = 8
substituting x = 8 in the 2nd equation
3*8 + y = 23
24 + y = 23
y = -1
solution - (8,-1)
