If m and n are integers, is m odd?
(1) n + m is odd.
(2) n + m = n2 + 5
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
m-5=n(n-1),判断n(n-1)为偶数,odd-5=偶数,可以得出m=odd
【陷阱,一定要思考B单独是否正确】简单变形:n(n-1)=m-5 n(n-1)为偶数,所以m=5+even , m为odd
m-5=n(n-1)
n(n-1)为偶 m-5为偶 m为奇
(1)n奇 m偶 or n偶 m奇==>NS
(2)if n奇=>n+m=偶=>m奇;if n偶=>n+m=奇=>m奇==>S
注意平方不会改变数字奇偶性==
不要被条件一带跑
啊啊啊为啥会错
选项A肯定不满足,选项B带入“奇/偶”四种情况,即可得出,M一定是奇数
注意,奇数²为奇数!!!,所以Bsufficient
m-5=n(n-1),判断n(n-1)为偶数,odd-5=偶数,可以得出m=odd
m-5=n(n-1)
1)问什么不能n是奇数m是偶数呢
(2)分别假设n是odd和even时,m都是odd