|
M a s h q l a r
89
I
II
III
IV
c
d
c
b
a
289.
Nuqtalar o‘rniga qanday birhadlarni yozsangiz tenglik
to‘g‘ri bo‘ladi:
1) (2
a
– 5
b
)(... – ...) = 6
a
3
– 15
a
2
b
– 14
ab
+ ...;
2) (... – ...)(6
x
2
– 5
y
2
) = 12
x
3
+ 42
x
2
y
– ... – 35
y
3
;
3) (3
a
+ 4
c
)(... + ...) = 20
ac
+ 8
bc
+ 6
ab
+ ...;
4) (... + ...)(2
a
+ 5
b
) = ... + 5
ab
+ 8
ac
+ 20
b
?
290.
1)
(
) (
)
+
-
-
;
0,2
0,2
x
y z
x y
2)
(
) (
)
0,3
0,3
;
-
+
x
y z
x y
+
291.
1)
(
) (
) (
)
3 ;
a
-
-
a b a+ b
b
3)
(
) (
) (
)
3
2 ;
-
+
x +
x
x
3 2
1
2)
(
) (
) (
)
3 ;
+
-
+
a b a b a
b
4)
(
) (
) (
)
2
1 4
3 .
-
+
-
x
x
x
3
292.
1) Tenglikning to‘g‘riligini isbotlang:
c
2
+
b
(
a
-
c
) + (
b
+
d
-
c
)
c
+
d
(
a
-
c
) =
a
(
b
+
d
);
2) To‘g‘ri to‘rtburchakning yuzini hisoblash uchun ikkita
ifoda tuzing (14- rasm).
To‘g‘ri to‘rtburchakning yuzi I, II, III, IV to‘g‘ri to‘rt-
burchaklar yuzlari yig‘indisiga tengligidan foydalaning va
1- tenglikka geometrik talqin bering.
293.
1) Quyidagi shaklning yuzini va perimetrini hisoblash
uchun formulalar tuzing (15- rasm):
2) Shakl yordamida:
a)
a
(
c
+
d
) =
ac
+
ad
;
15- rasm.
14- rasm.
k
a
l
n
d
c
a
90
b)
a
· (
k
+
l
+
n
) =
ak
+
al
+
an
tengliklarni isbotlang. Bu
formulalarning geometrik ma’nosini oching.
294.
1)
ABCD
to‘g‘ri to‘rtburchakning (16- rasm) yuzi
(
) (
)
a b c d
ac bc ad bd
+
+
=
+
+
+
ekanligini ko‘rsating.
2)
ABFE
to‘g‘ri to‘rtburchakning (17- rasm) yuzi
(
) (
)
a b c d
ac bc ad bd
+
-
=
+
-
-
ekanligini ko‘rsating.
Birhad va ko‘phadni birhadga bo‘lish
Bir nechta birhad va ko‘phadlarni qo‘shish, ayirish, ko‘-
paytirish va natural ko‘rsatkichli darajaga ko‘tarish natijasida
yana ko‘phad hosil bo‘lishi oldingi paragraflarda ko‘rsatildi. Sa-
nab o‘tilgan bu amallar ichida bo‘lish amali uchramadi. Bo‘-
lish amalini o‘z ichiga olgan ifodalar V bobda batafsil qaraladi.
Ba’zan bo‘lish natijasida ham ko‘phad hosil bo‘ladi.
1. Birhadni birhadga bo‘lish
Masala.
32
a
3
b
2
birhadni 4
a
2
birhadga bo‘ling.
Sonni sonlar ko‘paytmasiga bo‘lish xossasidan foydalana-
miz: sonni ko‘paytmaga bo‘lishda shu sonni ko‘paytmaning
birinchi ko‘paytuvchisiga bo‘lish kerak, so‘ngra hosil bo‘lgan
natijani ikkinchi ko‘paytuvchiga bo‘lish kerak va hokazo. Na-
tijada,
18-
16- rasm.
17- rasm.
B
E
C
M
A
a K
b
D
F
c
d
M
N
K
B
A
P
E
F
a
b
c
d
91
(
) ( ) (
)
=
3 2
2
3 2
2
32
: 4
32
: 4 :
.
a b
a
a b
a
Endi ushbu qoidani qo‘llaymiz:
ko‘paytmani songa bo‘lishda
ko‘paytmaning ko‘paytuvchilaridan birini shu songa bo‘lish kerak.
U
holda
(
)
(
)
=
=
3 2
3 2
3 2
32
: 4
32 : 4
8
;
a b
a b
a b
(
)
(
)
=
=
3 2
2
3
2
2
2
8
:
8
:
8
.
a b
a
a
a b
ab
Shunday qilib,
(
) ( )
=
3 2
2
2
32
: 4
8
.
a b
a
ab
Birhadlar boshqa hollarda ham xuddi shunday bo‘linadi,
masalan,
(
)
2 3
2 3
:
4
4
1;
a b
a b
=
(
) (
)
4 2
2
2
66
: 22
3
;
c
=
a b
a b
a bc
(
) (
)
2 2
2
2
9
:
3
3 .
-
= -
2
k n m
kn m
k
Bo‘lish natijasini ko‘paytirish bilan tekshirish mumkin:
bo‘linuvchi bo‘luvchining bo‘linmaga ko‘paytmasiga teng bo‘lishi
kerak.
Masalan,
(
) (
)
5 3
2
3
56
: 7
8
c
=
a b
a b c
a b
2
— bo‘lish to‘g‘ri baja-
rilgan, chunki
(
)
5 3
2
3
56
8
.
=
a b c
a b c
a b
2
7
2. Ko‘phadni birhadga bo‘lish
Masala.
2
a
2
b
+ 4
ab
2
+ 8
abc
ko‘phadni 2
ab
birhadga bo‘ling.
Ushbu qoidadan foydalanamiz:
yig‘indini songa bo‘lishda
har bir qo‘shiluvchini shu songa bo‘lish kerak,
ya’ni
(
)
(
)
(
)
(
)
+
+
=
+
2
2
2
2
4
8
: 2
2
: 2
a b
ab
abc
ab
a b
ab
(
)
(
) (
) (
)
+
+
= +
+
2
4
: 2
8
: 2
2
4
ab
ab
abc
ab
a
b
c.
Ko‘phadni birhadga boshqa hollarda ham xuddi shunday
bo‘linadi, masalan,
(
) (
)
-
+
=
3 2
2 3
2 2
2 2
9
3
: 3
a b
a b
a b
a b
(
) (
) (
) (
) (
) (
)
=
+ -
+
=
-
3 2
2 2
2 3
2 2
2 2
2 2
1
3
9
: 3
3
: 3
: 3
3
.
a b
a b
a b
a b
a b
a b
a b+
92
Ko‘phadni birhadga bo‘lish uchun ko‘phadning har bir
hadini shu birhadga bo‘lish va hosil bo‘lgan natijalarni
qo‘shish kerak.
Ko‘phadni birhadga bo‘lish natijasini ko‘paytirish bilan
tekshirish mumkin. Masalan,
(
) (
)
-
=
-
4
2
2
4
2
2
2
2
36
45
: 9
4
5
n m
n m
n m
n
m
bo‘lish to‘g‘ri bajarilgan, chunki
(
) (
)
-
=
-
4
2
2
4
2
2
2
2
36
45
4
5
9
.
n m
n m
n
m
n m
Ko‘rilgan misollarda birhad (ko‘phad)ni birhadga bo‘lish
natijasida birhad (ko‘phad) hosil bo‘ladi. Bunday hollarda
ko‘phad birhadga qoldiqsiz bo‘linadi, deyiladi. Ammo ko‘p-
hadni birhadga qoldiqsiz (butun) bo‘lish hamma vaqt ham
mumkin bo‘lavermaydi. Masalan,
ab
+
ac
ko‘phad
ab
birhadga
qoldiqsiz (butun) bo‘linmaydi.
Birhad (ko‘phad)ni birhadga bo‘lishda harflar bo‘luvchi
nolga teng bo‘lmaydigan qiymatlarni qabul qiladi, deb faraz
qilinadi.
Bo‘lishni bajaring
(295
–
305):
295.
1)
5
2
:
;
b
b
2)
11
7
:
;
y
y
3)
7
7
:
;
a
a
4)
b
b
9
9
:
.
296.
1)
: ;
12
4
x
2)
(
)
-
: ;
15
5
a
3)
(
)
-
: ;
18
6
y
4)
( )
10
2
c
-
:
.
297.
1)
( )
-
8 :
2 ;
c
2)
2
3
: 5;
a
3)
-
1
2
: 2;
b
4)
-
1
3
3 :
.
c
298.
1)
( )
-
2
5
:
2 ;
x
2)
(
)
-
-
7
9
7
:
;
m
3)
-
-
8
9
3
:
;
4
a
4)
16
4
25
5
:
.
299.
1)
: ;
a
5
a
2)
: ;
x
8
x
3)
( )
:
;
a
-
5
a
4)
(
)
( )
:
.
-
-
7
y
y
M a s h q l a r
93
300.
1)
(
)
( )
-
: 2
;
6
x
x
3)
(
)
(
)
:
3
;
-
-
6
xy
xy
2)
( )
:
;
15
5
z
z
4)
(
)
12
:
4
.
-
ab
ab
301.
1)
1
2
3 :
;
a
a
3)
(
)
-
1
3
:
;
c
c
5
2)
-
:
;
b
b
2
2
3
5
4)
(
)
(
)
-
: 1,3 .
n
n
1,69
302.
1)
(
)
8
:
;
-
abc
a
4
3)
(
)
(
)
-
-
:
;
6,4
4
xy
x
2)
(
)
( )
10
: 6 ;
-
pq
q
4)
(
)
(
)
:
0,6
.
-
-
0,24
abc
ab
303.
1)
( )
14
:
;
a
a
5
2
7
3)
(
)
(
)
-
-
:
;
10
10
0,2
a
a
2)
(
)
( )
42
: 6
;
-
m
m
7
4)
(
)
-
-
:
2
.
a
a
17
17
1
3
2
304.
1)
-
3 2
2
2 2
2
1
2
3
3
:
;
m n p
m n p
3)
(
) (
)
-
2
28,9
:
;
y
2
3
2 3
1,7
p q
p y
2)
-
-
4 3 2
3
2
1
2
2
3
1
:
;
a b c
a bc
4)
(
)
(
)
-
-
6
:
2
.
c
3 2
2
a b
a bc
305.
1)
3
3
20
:
;
-
m
n
m n
4
2
5
3)
-
-
3 2
2
2
1
:
5
2
;
4
3
a x y
a xy
2)
(
) (
)
-
2 3
1,3
: 16,9
;
3
2
a x y
a xy
4)
-
-
3
2
3
1
4
2
:
1
.
2
5
a b c
a b c
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