x+4y=8 2x-5y=29

Let's solve the first equation for 'x'

x=8-4y    Now substitute this value for 'x' in the second equation:

2 (8-4y) - 5y = 29

16 -8y -5y = 29

-13y=13

y=-1     Substitute this value of y into one of the equations to get 'x'

x=8-4y  = 8 -4(-1) =8+4= 12