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
Divide by each number below it and find that each does not come out to a whole number except for dividing by 1
Answer:
D
Step-by-step explanation:
Please helpppppoo I’m so lost
Answer:
A. -1,2
Step-by-step explanation:
take point B move it 7 units (positive) across the x axis then from there 5 units (negative) down. That point lands on (-1,2) so B’ has the new point of that
Answer:
24 times
Step-by-step explanation:
cone is used to fill cylinder
conevolume times x=cylindervolume
so
x=cylinderv/conev
cylinderv=hpir^2
conevolume=1/3hpir^2
cylinder:
v=hpir^2
r=10
h=20
v=20*pi*10^2=2000π
cone=1/3hπr²
r=5
h=10
v=1/3(10)π5²=250π/3
volume of cylinder ÷ volume of cone
= 2000π ÷ (250π÷3)
= 6000π ÷ 250π
= 600÷25
= 24
please mark me brainliest
