For example fill ur bathtub full of water. then lay down in the tub the water leaving the tub is the force acting back.
Answer:
the answer to your question is x = 5
1/7x - 6 = 8(11-3)
1/7x - 6 = 8(8)
1/7x - 6 = 64
1/7x = 70
1/7 = 70x
1 = 490x
1/490 = x