Thread: Set's Of numbers

A set of n numbers has the sum s. Eachh number of the set is increased by 20 nultipled by 5 and then decreased by 20. what is the sume of the nmber the new set in terms of s and n

Hello, Godfather!

I'll baby-step through this one . . .

A set of n numbers has the sum S.
Each number of the set is increased by 20, multipled by 5 and then decreased by 20.
What is the sum of the numbers of the new set in terms of S and n ?

The original set is: .a + b + c + ... + n .= .S

Each number x is changed like this: .5(x + 20) - 20 .= .5x + 80

The new sum is: .(5a + 80) + (5b + 80) + 5a + 80) + ... + (5n + 80)

. . = .5(a + b + c + ... + n) + (80 + 80 + 80 + ... + 80)
. . . . . . . . . . . . . . . . . . . . . . \__________________/
. . . . . . . . . . . . . . . . . . . . . . . . . . . .n terms

Therefore, the new sum is: .5S + 80n