Answer:
f = 
Step-by-step explanation:
1. 4(4f - 9) = -(2-f) distribute the negative
2. 4(4f - 9) = -2 + f Distribute the 4
3. 16f - 9 = -2 + f Subtract f on both sides
4. 15f - 9 = -2 Add 9 on both sides
5. 15f = 7 Divide both equations by 15
6.
f = 
Answer:
<h2>780</h2>
Step-by-step explanation:
What is the sum of the series 5^n from n=1 to 4.
5^1 + 5^2 + 5^3+ 5^4 =
5 + 25 + 125 + 625 =780
Since the area of a square is equal to the square of one of its side's length, then the area should be equivalent to

.

---> equation (1)
By using pythagoras rule which states that the

---> equation (2)
where the opposite side's length is 8 and the hypotenuse side's length is 10
by substituting by the values in equation (2) therefore,

substitute this value in equation (1) then

where A is the area of the square whose side is x