What’s the difference between subject and topic

Explanation:

The confusing thing is that topic and subject are sometimes not clearly distinguishable. The person or thing that is the main focus of the sentence is called the topic. The subject of the sentence is not always the topic.  Subject of the sentence is  Weather  while the topic of the sentence is Today .

d. the two authors are in awe of nature; their experiences, reveal that time in nature can change people.

explanation:

substitute y = 2x - 4 to x + 2y = 12:

x + 2(2x - 4) = 12     use distributive property

x + (2)(2x) + () = 12

x + 4x - 8 = 12     add 8 to both sides

5x = 20     divide both sides by 5

x = 4

put the value of x to the first equation:

y = 2(4) - 4

y = 8 - 4

y = 4