Answer:
S₁₅ = 645
Step-by-step explanation:
The sum to n terms of an arithmetic sequence is
=
[ 2a₁ + (n - 1)d ]
where a₁ is the first term and d the common difference
Using the nth term formula
= 5n + 3 , then
a₁ = 5(1) + 3 = 5 + 3 = 8
a₂ = 5(2) + 3 = 10 + 3 = 13 , then
d = a₂ - a₁ = 13 - 8 = 5
Thus
S₁₅ =
[ (2 × 8) + (14 × 5) ]
= 7.5( 16 + 70)
= 7.5 × 86
= 645
Answer:
2967 yes votes
Step-by-step explanation:
Welcome to Brainly!
One way of doing this problem follows:
Find the ratio, r, mentioned in the problem statement. To do this,
write the equation 3r + 5r = 7912 and solve this for r:
8r = 7912, so that r = 989.
Then the number of yes votes was 3(989), or 2967, and the number of no votes was 5(989), or 4947.
check: Does the ratio 2967/4947 equal 3/5? yes.
There were 2967 yes votes.
Answer:
t=-6
Step-by-step explanation:
So you have a right angle triangle. You need to use trig for this, as you have two values you can figure out a third.
You know that you have
90 deg. angle
19 deg. angle
Therefor you have 71 deg. angle
sin19 = x/15
15sin19 = x
x = 2.2
Now do Pythagoras c^2-b^2=a^2
a = 14.8
So the sides are 2.2 and 14.8 units long. (If these numbers are wrong tell me and I'll edit answer)