a + x = a
=> x = 0
a + x > a
=> x \(\in\) N*
a + x < a
=> x = \(\varnothing\)
a + x = a
=> x = 0
a + x > a
=> x \(\in\) N*
a + x < a
=> x = \(\varnothing\)
viet cac tap hop sau
a, tap hop acac so tu nhien x ma x - 11 = 20
viet cac tap hop sau = cach chi ra tinh chat dac trung cho cac phan tu cua tap hop ?
a, tap hop X cac so tu nhien lon hon 0 va nho hon hoac bang 10 ?
b, tap hop Y cac so tu nhien co 2 chu so ?
c, tap hop M cac so tu nhien16 ; 25 ; 36 ; 49 ; 64 ; 81 ?
cho tap hop A cac so tu nhien co 2 chu so , biet chu so hang don vi gap doi chu so hang chuc
a, hay liet ke cac phan tu cua tap hop A
b, viet tat ca cac tap hop con cua A co 2 phan tu
c, viet tat ca cac tap hop con cua A cp 3 phan tu
tap hop A la tap hop gom cac so tu nhien co 3 chu so va tong cac chu so bang 2. Hoi tap hop A co bao nhieu phan tu?
Tim tap hop cac so nguyen x sao cho
A, |2x - 4| + 2x - 4 = 0
B , |x + 5|- ( x +5) = 0
C, 2 - x = - |2- x|
tinh tong
a, S = 2 + 4 + 6 + .......... + 100
b, Tim so phan tu cua mot tap hop cac so tu nhien co 3 chu so va tinh tong tim duoc
cho B = { a b c x y z } viet cac tap hop con cua tap hop B sao cho moi tap hop co 2 phan tu ? co bao nhieu tap hop con nhu the ?
Tim cac so tu nhien x va y sao cho:
a) (2x-3)(3y-2)=1
cho tap hop A = {a , b , c } viet cac tap hop con cua tap hop A sao cho moi tap hop con ay chua it nhat 1 phan tu ? co bao nhieu tap hop ?