Answer:
....................21 .....................
1.25x
because 25% can be represented as 0.25. so as the new price would be 125% of the old one its 1.25x
Answer:

Step-by-step explanation:
Given


Required
The explicit formula
First, calculate 
Set n=2; So:


Substitute -25 for 


Calculate the common difference (d)



So, the nth term is:


Open bracket

Collect like terms


Answer:
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Answer:
1250 m²
Step-by-step explanation:
Let x and y denote the sides of the rectangular research plot.
Thus, area is;
A = xy
Now, we are told that end of the plot already has an erected wall. This means we are left with 3 sides to work with.
Thus, if y is the erected wall, and we are using 100m wire for the remaining sides, it means;
2x + y = 100
Thus, y = 100 - 2x
Since A = xy
We have; A = x(100 - 2x)
A = 100x - 2x²
At maximum area, dA/dx = 0.thus;
dA/dx = 100 - 4x
-4x + 100 = 0
4x = 100
x = 100/4
x = 25
Let's confirm if it is maximum from d²A/dx²
d²A/dx² = -4. This is less than 0 and thus it's maximum.
Let's plug in 25 for x in the area equation;
A_max = 25(100 - 2(25))
A_max = 1250 m²