Answer: The correr solution is 
Step-by-step explanation:
Since the steps in Lin's solution are not shown, we are not able to find her erros. However, we can solve it step by step and find the correct result:

Firstly, in the left part of the equation we have to multiply
by the numbers inside the parenthesis; and in the right side we have to solve first what is inside the parenthesis:

Adding similar terms in the left side and multiplying
by the number inside the parenthesis in the right side:

Isolating
:
This is the correct solution
Answer:
3x+9
Step-by-step explanation:
i think since it is across from there
Answer:
the 2nd answer (II)
Step-by-step explanation:
1 and 2 are not rational if that's what your asking
Answer: 1 hour 20 minutes
Step-by-step explanation:
Given : The old machine could shred a truckload of paper in 4 hours.
Rate of work done by old machine = 
The new machine could shred the same truckload in 2 hours.
Rate of work done by new machine = 
Let 't' be the time taken by both of them working together , then we have the following equation:-

Since 1 hour = 60 minutes
Then, 
Hence, it will take 1 hour 20 minutes to shred the same truckload of paper if Ron runs both shredders at the same time.