Answer: 19.5
Step-by-step explanation:
Use Pythagorean theorem to find the diagonal as it is a right triangle.
Answer: The explicit rule for the geometric sequence is:
an=(2/5) (5)^(n-1), for n=1, 2, 3, 4, ...
Solution:
a1=2/5
an=5 (an-1)
n=2→a2=5 (a2-1)= 5 (a1)= 5 (2/5)→a2= (2/5) (5)
n=3→a3= 5 (a3-1)= 5 (a2)= 5 [(2/5) (5)]=(2/5) (5)^(1+1)→ a3=(2/5) (5)^2
n=4→a4= 5 (a4-1)= 5 (a3)= 5 [(2/5) (5)^2]= (2/5) (5)^(2+1)→ a4=(2/5) (5)^3
a1=2/5=(2/5) (1)=(2/5) (5)^0→a1=(2/5) (5)^(1-1)
a2=(2/5) (5)=(2/5) (5)^1→a2=(2/5) (5)^(2-1)
a3=(2/5) (5)^2→a3=(2/5) (5)^(3-1)
a4=(2/5) (5)^3→a4=(2/5) (5)^(4-1)
Then:
an=(2/5) (5)^(n-1), for n=1, 2, 3, 4, ...
Answer:
C) 
Step-by-step explanation:
0.51 repeating decimal
x= 0.51515151
multiply by 100 on both sides
100x = 51.515151.........
x= 0.515151...............
--------------------------------------------(subtract)
99x = 51
divide by 99 on both sides

divide both sides by 3

f(-2) means replace x in the equation with -2, then solve:
-2^2 +5(-2)
Simplify:
4 + -10
Add:
-6