The slope is 1
All you need to do is look on the graph and count how many times you go up or down and to the side and then divide. Super simple!
Answer:
3 machine
Step-by-step explanation:
It is given that 6 machine each working at the same rate can complete the work in 12 days
We the has to complete in 8 days
Let we need x extra machine to complete the work in 8 days
So total number of machines =x+6
Now according to man work day equation 



x=3 machine