First, try deleting the x-coordinate from the equations by making them the same number. By doing that I multiplied the first equation (-7x+8y=1) by 4 and (4x-8y=20) by 7. That got me -28x+32y=4 and +28x-56y=140. You could cross out the 28 which gets +32y=4 and -56y=140. Then add up both equations. It’s gets you -24y=144