Question

find the sum of 1st 15 multiples of 8​

Answer 1

Step-by-step explanation:

8+16+24+32+40 : 120

thanks

Answer 2

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Sn=n/2(2a+(n-1)d)

S15 = 15/2(2×8+(15-1)8

= 15/2(16+(14)8)

= 15/2(16+112)

= 15/2 x 128

= 15 x 64

= 960

The sum of the first 15 multiples of 8 is 960.

Step-by-step explanation:

hope it helps you