Tiết 98 - Bài 15 - Tìm một số khi biết giá trị một phân số của nó

1
Trêng PTDT néi tró Mï cang ch¶i
GV: Nguy n Nh Ho ngễ ư à

2





 =⋅
4x.
11
8
b) =





 =⇒


 =⇒




 ⋅=⇒




⋅=⇒



=⇒


 =⇒

3
TiÕt 97
Ngêi so¹n: §ç ThÞ Minh Anh
Trêng THCS Lª Quý §«n
CÇu GiÊy – Hµ Néi

4




=⋅

Tr¶ lêi
 !" !#$%&'($)*∈+,
x
5
3
⋅

45
3
5
27
5
3
: 27 x =⋅==
-$%&'(!. !"
⇒ !" !#$%&'($)


 !" !#$%&'($)/"0
12$%&'(!.3" 4 !" 5
5
3

5
67!
8"9!#".:";
" *<"∈+
,

"

"



n
m

:ax =
1!#:"; 

n
m
*<"∈+,

5
=$
=

89>! ?@A"B%!<C D"; =$"B%!
 3";>!E"$/9$BF";:";";! >0
12>")! ?@BF!3" 4$"B%!5
=

GH;I
GBF";"B%!@JD";! & A">$)
>! *";
=

=

 =−
⇒!#>:";=$
=

->! ?@BF!
*$===


=
=
=

= =⋅=


K 3" E"L)3@M&M"@N";" O3";!M!!P
9
<


<(0 =⋅
4,87,2:
3
2
B. =
!#".:";<
3
2
=<


<Q0 =
3,5 -
7
3
1 . 5- A. =
7
50

)5(:
7
10
C.
−
=−
!#".:";R



R<

=
RS0 =

TU"L)3! V! O3";!M!!P
y
x
a
⋅
8"!#! 3B%!*<∈+<≠=
"  0… …
y
x
8" 0$O@." P"L%& P"0……
;MW& P"!#9! 3B%!
!8"9!#".:";*<"∈+<"≠=
"  0… …
n
m

n
m
:a
8" $O…… *<∈+,
b
a
:c
9!#".:";!
b
a




9<X!#".:";<


S/"("@J@Y& Z&" " B
006,0
500
2
. 1,5%
5
2
. 1,5
==
 [3[</"("@J@Y& Z&" @N"; 5
<

==

<
==

<X


<
=⋅==




3";\!.<X]0" $BF";\3";9
! <:";$BF";]3";! \")$);
GH;I
!.<X!#$BF";\3";! $);0
-$BF";\3";! $)
==*;
===

<X ==




T[@BF!9)
9"^@.:";






S/"("@!9!"M! 3";";)
+;) ?" O/"@!";0
+;) ? /"@!";!E"$/0
+;) ?/"@!"_=";0
12Q"M! !.3" 4";5
3
1
8
5




<*K ";–
<<*S ";–

14
TiÕt 98