$\text{Bài 1 :}$
$\text{A = { 1 + 3x / 0 ≤ x ≤ 6 }}$
$\text{B = { x³ / 1 ≤ x ≤ 5 }}$
$\text{C = { x ( x + 1 ) / 1 ≤ x ≤ 6 }}$
$\text{Bài 2 :}$
$\text{a) A = (a) ; (b) ; (c) ; (d) }$
$\text{b) B = (a , b) ; (a , c) ; (a , d) ; (b , c) ; (b , d) ; (c , d)}$
$\text{c) C = (a , b , c ) ; ( b , c , d ) }$
$\text{Chúc em học tốt ^^}$
$\text{( Mong Admin đừng Xóa )}$