This is a physics problem.
The law is that the momentum is preserved: total momentum before collsion = total momentum after collision
Momentum before collision = 80 kg.m/s - 100 kg.m/s = -20 kg.m/s
Then answer is b. - 20 kg.m/s
Always foucus on the teacher ask help when needed
Slope intercept form is
y = mx + b
where m is the slope and b is the y intercept.
Here we have
y = 9x - 2
so a slope of 9 and y intercept of -2
Answer: third choice
