a rectangular game board is composed of identical squares arranged in a rectangular array of r rows
a:r^2-r
b:r^2-1
c:r^2
d:r^2+1
e:r^2+r
a rectangular game board is composed of identical squares arranged in a rectangular array of r rows and r+1columns.the r rows are numbered from 1 through r,and the r+1 columns are numbered from r through r+1,if 人》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
人气:298 ℃ 时间:2020-01-31 23:28:24
解答
本题选a!
就是r*(r+1)格中去掉第4行第7列的格子后还有几格,
所以
共有:r*(r+1)-(r+r+1)+1
=r^2+r-2r-1+1=r^2-r.
推荐
猜你喜欢
- 同学们做红花120朵,红花朵数比做的黄花朵数少25%,做黄花多少朵?
- 什么是动量守恒定律
- 1.put up your coat on the hook.2.put up the notice on the bulletin board.
- 连词成句;1,home,Bob,Uncle,is,at,cooking 2,France,windy,in,it,in,is,winter
- 六年级上册英语第三单元let's read第二个 翻译
- 在比例尺为1:2000000的地图上,量得甲、乙两地的距离为3.6厘米.如果汽车以每小时36千米的速度从甲地到
- 一道阅读题《大自然的声音》
- 一加二分之三减x等于三分之x加四减二 的解是多少