3x-10y-29=0
-11x-10y+13=0
Rearrange.
3x-10y = 0 + 29 3x - 10y = 29 ...........(i)
-
-11x-10y = 0 -13 -11x - 10y = -13.........(ii)
_____________
14x + 0y = 42
We subtract. Equation (i) - (ii)
3x - (-11x) = 3x + 11x = 14x
29 - (-13) = 29 + 13 = 42, -10y - (-10y) = 0
14x = 42
x = 42/14
x = 3.
Substituting x = 3, into (i), 3x - 10y = 29, 3*3 - 10y = 29
9 - 10y = 29
-10y = 29 - 9
-10y = 20
y = 20/-10
y = -2
Therefore x = 3, and y = -2.
Hope this helps.