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
17) 
18) 
19) 
20) 
Step-by-step explanation:
17) The difference between a number and 8 is 11
Let number = x
then the equation will be:

Solving:


18) Nine less than a number is five.
Let number = x
then the equation will be:

Solving:

19) Seven is equal to a number plus 6
Let number = x
then the equation will be:

Solving:

20) The sum of a number and -4 is -18
Let number = x
then the equation will be:

solving:

Keywords: Algebraic Expressions
Learn more about Algebraic Expressions at:
#learnwithBrainly
Answer: 3 1/6
Explanation:
1. divide the numerator by the denominator
2. write down the whole number result
3. use the remainder as the new numerator