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## Comment on

Removing x From Set A## Sum1 = MN

Sum2 = (M-3) (N-1)

sum2 = MN - 3N - M + 3

Sum2 = Sum1 - 3N - M + 3

since Sum1 is greater that Sum2

Sum1 - Sum2 = 3N + M - 3

LHS gives removed value that is X

X = 21 - 3

X = 18.

## I think I figured out an

1) Sum = (mean)(n) --> Sum = MN

2) Sum - x = (M-3)(N-1)

Substitute 1) into 2):

MN - x = (M-3)(N-1)

MN - x = MN - M - 3N + 3

- x = - M - 3N + 3

x = M + 3 N - 3

x = (21) - 3

x = 18

## Perfect!

Perfect!