Answer:


Step-by-step explanation:
Given


Solving (a): T7
Substitute 7 for n in 


Calculate S7 and S6



So:


Solving (b): Tn

Where 
Calculate
We have:

Open brackets



So:



Collect Like Terms


it take him 90 hrs to plow 60 acres
Answer:
8
Step-by-step explanation:
(10-4)+20/20
6+20/10
6+2
8
Answer: .045
Step-by-step explanation:.75=.750 so, 750-705=.045
Hope this helps!
Answer:
Let the distance between woman and pole be "x".
From diagram,
In ΔOAB,
tan 18 = 
tan 18 = 
∴ x =
................ (1)
In ΔOBC
tan 14 = 
tan 14 = 
y = x × tan 14 ..............(2)
equating (2) in (1), we get;
x = 
x = 
∵ tan 18 + tan 14 = 0.574
<em>∴ x = 113.2 ft</em>
<em>i.e. The her distance from the pole is 113.2 ft.</em>