a) 73² - 27²

= ( 73 + 27 ) ( 73 - 27 )

= 100 . 46

= 4600

b) 37² - 13²

= ( 37 + 13 ) ( 37 - 13 )

= 50 . 24 

= 1200

c) 2002² - 2²

= ( 2002 + 2 ) ( 2002 - 2 )

= 2004 . 2000

= 4008000

letrunghieu sai

câu c bạn viết thiếu mjk viết lại

a)73^2 - 27^2

=(73+27)(73-27)

=100.46

=4600

b)37^2 - 13^2

=(37+13)(37-13)

=50.24

=1200

c)2002^2 - 2^2

=(2002+2)(2002-2)

=2004.2000

=4008000

a: \(73^2-27^2=\left(73-27\right)\left(73+27\right)=100\cdot46=4600\)

b: \(37^2-17^2=\left(37-17\right)\left(37+17\right)=20\cdot54=1080\)

c: \(2002^2-2^2=\left(2002-2\right)\left(2002+2\right)=2004\cdot2000=4008000\)

a) 73² - 27²
= (73 - 27)(73 + 27)
= 46 . 100
= 4600

b) 37² - 13²
= (37 - 13)(37 + 13)
= 24 . 50
= 1200

c) 2002² - 2²
= (2002 - 2)(2002 + 2)
= 2000 . 2004
= 4008000

a ) 73² - 27² = 43²

b ) 37² - 13² = 24²

c ) 2002² - 2² = 1998²

a) \(75^2-25^2=(75-25)(75+25)=50.100=5000\)

b) \(37^2 - 13^2=(37-13)(37+13)=24.50=1200\)

c) \(2002^2 - 2^2=(2002-2)(2002+2)=2000.2004=4008000 \)

Câu a :

\(75^2-25^2=\left(75-25\right)\left(75+25\right)=50.100=5000\)

Câu b :

\(37^2-13^2=\left(37-13\right)\left(37+13\right)=24.50=1200\)

Câu c :

\(2002^2-2^2=\left(2002-2\right)\left(2002+2\right)=2000.2004=4008000\)

a)7²  -27² =(7-27)(7+27)

=-20.34

=-680

b)37² -13²=(37-13)(37+13)=24.50

=1200

c)2002²-2²=(2002-2)(2002+2)

=2000.2004

=4008000

a)\(69^2-31^2=\left(69-31\right)\left(69+31\right)=38.100=3800\)

\(1023^2-23^2=\left(1023-23\right)\left(1023+23\right)=1000.1046=1046000\)

\(c,\left(27+73\right)^2-2.27.73+54.73\)

\(100^2-54.73+54.73=10000\)

\(d,\left(63-13\right)^2+2.13.63-26.63=50^2=2500\)

\(73^2-27^2=\left(73+27\right)\left(73-27\right)\)

                     \(=100\cdot46=4600\)

\(2002^2-2^2=\left(2002-2\right)\cdot\left(2002+2\right)\)

                       \(=2000\cdot2004=4008000\)

hok tốt .

a) 162

a, -79(73-27) - 73(-79+27)

= [-79.73 - (-79).27] - [73.(-79) + 73.27]

=-79.73 + 79.27 + 73.79 - 73.27

=79.27-73.27

=27(79-73)

=27.6= 162

b,   vì 2n luôn luôn là số chẵn với mọi n thuộc N nên 

=> 2n + 1 là số lẻ

ta có:

-5².13.(-2)².(-1)²ⁿ⁺¹

^{= -25.13.4.(-1)}

^{=25.13.4= 1300}