Sh. A. Alimov, O. R. Xolmuhamedov, M. A. Mirzaahmedov

= a³ + 2a²b + ab² + a²b + 2ab² +b³ = a³ + 3a²b + Зяб² + b³. A Xuddi shunga o'xshash,
formulani ham isbotlash mumkin.

2. 
   va (4) formulalar mos ravishda yig'indining kubi va
   

1. 
   ayirmaning kubi deb ataladi.
   

! (3) va (4) formulalar ham qisqa ko'paytirish formulalari

1. 
   hisoblanadi.
   

Mashqlar
Quyidagi mashqlarda ikkihadning kvadratini ko'phad shaklida tasvirlang (365—372):

365. 
     1
     

2

365. 
     l
     

4) (x + 1) ;

3. 
   (7-m)²;
   
4. 
   (.y-6)²;
   

2) (3x + 2y)²; 3)(6a-4^; 4) (5*-/)².

l"² A + -
он—
2

367. 
     i
     
368. 
     i
     
369. 
     i
     
370. 
     i
     

(Зд²+1) ; 2) (a²+l) ; 3) (2х²+3и²) ; 4) (x²+j>²) , \2

/ , \² о 6 2 3

4)

2)

3)

m — 5

(0,2x + 0,3j>) ; 3) (0,46-0,5c)²; 4)

(ic + d) ;
(m- 2)²;
(x-3)²; (g + 2pf;

2 з 3 -x —
v³ 4,
'•«■-I*
4 5

3) (2 + x) ;
₄2

' l^² a-~
v 3,
/

\2

5. 
   (y + 3)‘
   
6. 
   (7 + mf.
   

5)
6)

/ \2 X у —+ —
3 4

1 2 371. 1) 2^fl3+I^{fl ;}

372. 
     1) (-4ab-5a²f
     

2. 
   (~3b²-2abf;
   
3. 
   (-8/?³ + 5p² )²;
   
4. 
   (l0x²-3xy³)\
   

3. 
   (0,2x² + 5x.y)²;
   
4. 
   (4лу + 0,5У)".
   

Qisqa ko'paytirish formulalaridan foydalanib, amallami bajaring
(373-375):

372. 
     1) (90-l)²; 2) (40 +1)²; 3) 101²; 4) 98².
     
373. 
     1) 999²; 2) 1003²; 3) 51²; 4) 39².
     
374. 
     1) 72² ; 2) 57²; 3) 997² ; 4) 1001².
     

Ifodani soddalashtiring (376—377):

372. 
     1) (x-y)²+(x + y)²; 3) (2a + b)² -(2a-bf;
     

2. 
   (x + j>)²-(x-j>)²; 4) (2a + bf + (2a-bf.
   

372. 
     1) (Зя-1)² +2 (1 + a)² ; 3) (x-1)² -(x + 1)²;
     

2. 
   3 (2-я)² +4 (fl-5)²; 4) -(3 + x)²+5 (1-x)².
   

Tenglamani yeching (378—379):

372. 
     1) 16x²-(4x-5)² =15; 3) -5x(x-3) + 5(x-1)² =-20; 2) 64х^г-(3-8х)² =87; 4) (2х-3)^г-(2x + 3)² = 12.
     
373. 
     1) (Зх-l)²-(3x-2)^! =0;
     

2. 
   (y-2) (^ + 3)-(^-2)² =5;
   
3. 
   (x + 3) (x + 7)-(x + 4)² =0;
   
4. 
   (у + 8)^г-(^ + 9) (j⁷—5) = 117.
   

o
113
o 8 —Algebra, 7-sinf

372. 
     Ifodaning qiymatini toping:
     

1. 
   9fl³-fl(3fl + 2)²+4а(За + 7), bunda a = -1-;
   

6

2. 
   (2^-5)² -4 (y-3)² -4y, bunda y =
   
3. 
   25/и(/и-1)-(5/и-3)²-6/и, bunda m = -0,3;
   
4. 
   24x² -(7x-2)² +(5x-3)(5x + l), bunda x = ~.
   

372. 
     x ni shunday birhadga almashtiringki, natijada tenglik bajarilsin:
     

1. 
   (x-4b⁷f =25a⁴b² -40a²b* + \6b'⁴\
   
2. 
   (x + 7c)² = 25b⁶ + 70b³с + 49c²;
   
3. 
   (10m⁵ + x)² = lOOm¹⁰ + 120mV + 36m⁴ n⁶;
   
4. 
   (5b² -xf =25b⁴ -30a²b³ +9a⁴b².
   

372. 
     Ifodani ikkihadning kvadrati shaklida tasvirlang:
     

1. 
   a²-l0ab + 25b²; 3) k⁴+2k²+1;
   
2. 
   25 + 10x + x²; 4) p²-l,6/? + 0,64.
   

x ni shunday birhadga almashtiringki, natijada ikkihadning kvad­rati hosil bo‘lsin (383—384):

372. 
     1) a² + 4a + x; 3) 36я²-х + 496²;
     

2. 
   p²-0,5p + x', 4) a²-6ab + x.
   

372. 
     1) m⁴-3m²+x\ 3) 4a²-5a+x;
     

2.