推 UncleGary :真巧 我也才剛剛做完這題 哈哈 11/29 15:29
→ UncleGary :就把行列各減一 變成 r*(r-1) = r^2-r 11/29 15:30
推 hi08060204 :r*(r+1) (總共方塊數) - r+(r+1)-1 (第4排7列方塊數) 11/29 15:31
→ jeff77766 :我喜歡三樓的解釋 (按讚) 11/29 22:22
A rectangular game board is composed of identical squares arranged in a
rectangular array of "r" rows and "r+1" columns. The "r" rows are numbered
from "1" through "r", and the "r+1" columns are numbered from "1" through
"r+1". If "r">10, which of the following represents the number of squares
on the board that are neither in the 4th row nor in the 7th column?
選項有
r^2-r r^2-1 r^2 r^2+1 r^2+r
抱歉平方只能這樣打
正確答案是
r^2-r
請問有人知道為什麼嗎
謝謝!
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