BÀI 5 X2 +4X +7 =(X+4) X2 7 X2 + 7 - X X2 7 4 X2 7 4X0 X27(...
1)
A
x
10 x
5
=
(
5)
10
5(
5)
x
25
25
25
25
x
x
x
x
5
x
5
(
5)
2
x
x
x
x
x
x
x
=
5
10
5
25
=
10
25
=
25
(
5)(
5)
=
5
5