Question

Find the sum of the following nine products: 1 × (10 – 1), 2 × (10 – 2), 3 × (10 – 3), … , 9 × (10 – 9)

Answer 1

9, 16, 21, 9

Explanation:

I hope this help and it was going in order

Answer 2

165

Explanation:

We solve the first 5

1*(10-1)=9

2*(10-2)=16

3*(10-3)=21

4*(10-4)=24

5*(10-5)= 25

and notice

when you go from 6 on its getting the same number because say 3*(10-3) = 3*7 and 7*(10-7) = 7*3 and 7*3 = 3*7 so

You add the first 5 integer you solved up

9 16 21 24 25 = 95

and then you double it no extra 25

and then you get 165 = answer