Ineed find the sum of the first 42 terms of the sequences (12, 16, 20,
a) 3,717
b) 3,948
c) 1,134
d) 4,032

B

Step-by-step explanation:

Note the common difference between consecutive terms of the sequence.

d = 16 - 12 = 20 - 16 = 4

This indicates the sequence is arithmetic with sum to n terms

= [2a₁ + (n - 1)d ]

where a₁ is the first term and d the common difference

Here a₁ = 12 and d = 4, thus

= [ (2 × 12) + (41 × 4) ]

                          = 21( 24 + 164) = 21 × 188 = 3948 → B

center= (-2,0)

radius= sqrt2/2

step-by-step explanation: