Find the sum of the arithmetic series in which a1 = –68, d = –3, and n = 20.

Sum = -1930

Step-by-step explanation:

Sum of an arithmetic series;

;Sum = n/2[ 2a1 + ( n - 1 )d]

Then substitute into the equation above

; Sum = 20/2 [ 2(-68) + (19)-3 ]

; Sum = 10 [ -136 - 57 ]

Therefore the sum of the arithmetic series

is; -1930

(a) the volume of the cone is 20/3 in3

hence, option a is correct.

dilation scale factor 2: starting with δabc, draw the dilation image of the triangle with a center at the origin and a scale factor of two. notice that every coordinate of the original triangle has been multiplied by the scale factor (x2). dilation with scale factor 2, multiply by 2.