bai giang toan pởepoin

Bµi 32 (sgk-trang 50)
Bµi 32 (sgk-trang 50)
6)x(x
6
6)x(x
x6x
6x
1
x
1
6x
1
5x
1
.....
2x
1
1x
1
1x
1
x
1
6)5)(x(x
1
5)4)(x(x
1
4)3)(x(x
1
3)2)(x(x

1
2)1)(x(x
1
1)x(x
1
+
=
+
−+
=
=
+
−=
+
−
+
+
++
+
−
+
+
+
−=
=
++
+
++
+
++

+
++
+
++
+
+

TiÕt 32
TiÕt 32
:
:
phÐp nh©n c¸c ph©n thøc
phÐp nh©n c¸c ph©n thøc


1) Quy t¾c : (sgk)
?2: Lµm tÝnh nh©n :
3
2x
13)3(x
13)(x
5
2x
)
2
3x(
2
13)(x
13x
2

3x
5
2x
2
13)(x
−−
=
=
−
−−
=
−
−
−











?3: thùc hiÖn phÐp tÝnh
?3: thùc hiÖn phÐp tÝnh
:
:
3)2(x

2
1)(x
3
3)1).2(x(x
3
1).(x
2
3)(x
3
3)2(x
3
1)(x
.
x1
96x
2
x
+−
−
=
+−−
−+
=
+
−
−
++

?4:tÝnh nhanh
?4:tÝnh nhanh

:
:


32
1533227
27153
153
27
.
32
.
27
4
153
3524
2435
35
24
2
35
+
=
++++−
+−++
=
=
++
+−
+

+−
++
x
x
)xx).(x).(x(x
)x).x.(xxx(
xx
xx
x
x
xx
xx

Bµi 40(sgk-trang53)
Bµi 40(sgk-trang53)
c¸ch 1:Sö dông tÝnh chÊt ph©n phèi :