Answer:
480
Step-by-step explanation:
Sn = n÷2 × (2a + (n-1)d)
n = 20 a = -14 d = 4
S20 = 10 × (-28 + 19 × 4) = 480
Answer:
$30.
Step-by-step explanation:
70/28 = 2.5
12 x 2.5 = 30
Answer:
6
Step-by-step explanation:
Splitting up the interval of integration into 
subintervals gives the partition
![\left[0,\dfrac1n\right],\left[\dfrac1n,\dfrac2n\right],\ldots,\left[\dfrac{n-1}n,1\right]](https://tex.z-dn.net/?f=%5Cleft%5B0%2C%5Cdfrac1n%5Cright%5D%2C%5Cleft%5B%5Cdfrac1n%2C%5Cdfrac2n%5Cright%5D%2C%5Cldots%2C%5Cleft%5B%5Cdfrac%7Bn-1%7Dn%2C1%5Cright%5D)
Each subinterval has length 
. The right endpoints of each subinterval follow the sequence
with 
. Then the left-endpoint Riemann sum that approximates the definite integral is
and taking the limit as 
gives the area exactly. We have
Answer:
For me,the answer will be A.
im not sure
correct me if im wrong
love ya
