Given nth term of an AP = 7-4n
Put n = 1 then t1 = 7-4(1) = 7-4 = 3
Put n = 2 then t2 =7-4(2) = 7-8 = -1
Common difference = t2-t1 = -1-3 = -4
Answer:
1. 
2. 
3a. 
3b. 3
3c. 
4. 
Step-by-step explanation:
1.
Rises 6 inches for every horizontal change of 16 inches
Slope = rise/run
Slope = 6/16
Slope = 3/8
2.
Rises 3 feet for every horizontal change of 12 feet
Slope = rise/run
Slope = 3/12
Slope = 1/4
3a.




3b.




3c.




4.

143, love :) Hope this helps