Answer:
Sum of the first 15 terms = -405
Step-by-step explanation:
a + 3d = -15 (1)
a + 8d = -30 (2)
Where,
a = first term
d = common difference
n = number of terms
Subtract (1) from (1)
8d - 3d = -30 - (-15)
5d = -30 + 15
5d = -15
d = -15/5
= -3
d = -3
Substitute d = -3 into (1)
a + 3d = -15
a + 3(-3) = -15
a - 9 = -15
a = -15 + 9
a = -6
Sum of the first 15 terms
S = n/2[2a + (n − 1) × d]
= 15/2 {2×-6 + (15-1)-3}
= 7.5{-12 + (14)-3}
= 7.5{ -12 - 42}
= 7.5{-54}
= -405
Sum of the first 15 terms = -405
P = A(1+r)^x
where P is the population at time x
A is the initial population and r is the growth/decay rate. Growth will be +positive r number added to the 1. Where as decay subtracts r. So any answers that are > than 1 which is answers A and B.
10/18 because 18-8=10 and the total amount is 18 so the fraction is 10/18
Answer:
You didn't provide the lines but I graphed it for you so you can match it up
Step-by-step explanation:
Answer:
x = 15
y = 7.5
Step-by-step explanation:
✔️Diagonals of a parallelogram bisect each other at 90°.
Therefore,
2x° + 60° + 90° = 180° (sum of triangle)
Solve for x
2x + 150 = 180
2x = 180 - 150
2x = 30
2x/2 = 30/2
x = 15
✔️2x = 4y (alternate angles/corresponding angles)
Plug in the value of x
2(15) = 4y
30 = 4y
30/4 = y
7.5 = y
y = 7.5
