bai1 viet cac tap hop sau theo hai cach
a) tap hop A cac so tu nhien le nho hon 10
b) tap hop B gom cac so tu nhien chan lon hon 10 nho hon 20
c) tap hop C gom 5 chu so chan lien tiep so nho nhat la 28
d) tap hop D cac so tu nhien gom 10 chu so le lien tiep trong do so lon nhat la 51
Đáp án:
a)
A={1,3,5,7,9,}
A={2k+1?/k∈N,2k+1<10
b)B={12,14,16,18}
B={2k?/k∈N,10<2k<20}
c)
C={28,30,32,34,36}
C={2k/k∈N ,2k≤28}
d)
D ={33,35,37,39,41,43,45,47,49,51}
D={2k+1/k∈N,2k+1≤51}
Giải thích các bước giải:
Đáp án:
a)
`A={1;3;5;7;9}`
`A={2k+1|k in N,2k+1<10}`
b)
`B={12;14;16;18}`
`B={2k|k in N,10<2k<20}`
c)
`C={20;30;32;34;36}`
`C={2k|k in N,2k_(min)=28}`
d)
`D={33;35;37;39;41;43;45;47;49;51}`
`D={2k+1|k in N,2k+1_(max)=51}`