If it already has the souce before it like for example it says " According to blank "Evidence" You still have to put the parentheses even though it is still there.
Answer:
7.9 Age Word Problems
One application of linear equations is what are termed age problems. When solving age problems, generally the age of two different people (or objects) both now and in the future (or past) are compared. The objective of these problems is usually to find each subject’s current age. Since there can be a lot of information in these problems, a chart can be used to help organize and solve. An example of such a table is below.
To pass on from one place or person to another or a electrical signal or a trait