Step-by-step explanation:
sum of the arithmetic sequence
a1 = 8
a2 = a1 + 8 = 8+8 = 16
...
an = 8×n
the sum of the first n elements of such a series is
n/2 × (2×a1 + (n - 1)×d]
with d being the difference between 2 consecutive elements (= the added constant).
so,
s30 = 30/2 × (2×8 + 29×8) = 15×(31×8) = 3720
Answer:
x = 4.5
Step-by-step explanation:
there's definitely other ways to solve this, but I used a proportion.

Then you can make this equation:
14x = 3.5 * 18
I solved for it and got 4.5 .
Answer:
4,2
Step-by-step explanation:
Isosceles mean two sides are same
My Question:
Why were there so many people on this question?
Answer:
84.5
Step-by-step explanation:
Use trig functions to find x. Trig functions are special relationships which exits between the sides of right triangles. Since you need to find x the hypotenuse and you have the adjacent side to 77 degree angle use cosine.
Cos 77 = 19/x
0.22495 = 19/x
19/0.22495 = x
84.5 = x