< = > 251x + 1996 = 16052

251x = 16052 - 1996 = 14056

x = 14056/251 = 56 

x*(123+128)=16052-1996

x*251=14056

x=14056:251

x=56

123*X+128*X+1996=16052

=> (123+128)*X=16052-1996

<=> 251*X=14056

=> X=14056/251

<=> X=56

123 * x + 128 * x + 1996 = 16052

(123 + 128) * x + 1996 = 16052

(123 + 128) * x = 16052 - 1996

(123 + 128) * x = 14056

x = 14056 / (123 + 128)

x = 56

\(\left(45\cdot46+47\cdot48\right)\cdot\left(51\cdot52-49\cdot48\right)\cdot\left(45\cdot128-90\cdot64\right)\cdot\left(1995\cdot1996+1997\cdot1998\right)\)

\(=\left(45\cdot46+47\cdot48\right)\cdot\left(51\cdot52-49\cdot48\right)\cdot\left(45\cdot2\cdot64-90\cdot64\right)\cdot\left(1995\cdot1996+1997\cdot1998\right)\)

\(=\left(45\cdot46+47\cdot48\right)\cdot\left(51\cdot52-49\cdot48\right)\cdot\left(90\cdot64-90\cdot64\right)\cdot\left(1995\cdot1996+1997\cdot1998\right)\)

\(=\left(45\cdot46+47\cdot48\right)\cdot\left(51\cdot52-49\cdot48\right)\cdot0\cdot\left(1995\cdot1996+1997\cdot1998\right)\)

\(=0\)

 (45 x 46 + 47 x 48) x (51 x 52 - 49 x 48) x (45 x 128 - 90 x 64) x (1995 x 1996 + 1997 x 1998)

=            A              x             B             x (45 x 128 - 45 x 2 x 64) x                C

= A x B x (45 x 128 - 45 x 128) x C

=A x B x 0 x C

=0

kết quả bằng 0

( 51 x 52 - 49 x 48 ) x ( 45 x 128 ) x ( 45 x128 - 90 x 64) x ( 1995 x 1996 x 1997)

= ( 51 x 52 - 49 x 48 ) x ( 45 x 128 ) x ( 5760 - 5760 ) x ( 1995 x 1996 x 1997)

= ( 51 x 52 - 49 x 48 ) x ( 45 x 128 ) x 0 x ( 1995 x 1996 x 1997)

= 0.

#Y/n

1) 1996 + 3992 + 5988 + 7984 
= 1996 x 1 + 1996 x 2 + 1996 x 3 + 1996 x 4 
= 1996 x ( 1 + 2 + 3 + 4) 
= 1996 x 10 = 19960 
2) 2 x 3 x 4 x 8 x 50 x 25 x 125 
= 3 x (2 x 50) x (4 x 25) x (8 x 125) 
= 3 x 100 x 100 x 1000 
= 30.000.000 
3(45 x 46 + 47 x 48) x (51 x 52 - 49 x 48) x (45 x 128 - 90 x 64) 
x (1995 x 1996 + 1997 x 1998) 
Ta thÊy : 45 x 128 - 90 x 64 
= 45 x 2 x 64 - 90 x 64 
= 90 x 64 - 90 x 64 
= 0 

1) 1996 + 3992 + 5988 + 7984 
= 1996 x 1 + 1996 x 2 + 1996 x 3 + 1996 x 4 
= 1996 x ( 1 + 2 + 3 + 4) 
= 1996 x 10 = 19960 
2) 2 x 3 x 4 x 8 x 50 x 25 x 125 
= 3 x (2 x 50) x (4 x 25) x (8 x 125) 
= 3 x 100 x 100 x 1000 
= 30.000.000 
3(45 x 46 + 47 x 48) x (51 x 52 - 49 x 48) x (45 x 128 - 90 x 64) 
x (1995 x 1996 + 1997 x 1998) 
Ta thÊy : 45 x 128 - 90 x 64 
= 45 x 2 x 64 - 90 x 64 
= 90 x 64 - 90 x 64 
= 0 

L I K E NHÁ BẠN^^

1  1996 + 3992 + 5988 +7984

= [ 1996 + 7984 ] + [ 5988 + 3392 ]

=           9980      +            9380

=                         19360

a, Ta có :

1996 + 3992 + 5988 + 7984

= 1 x 1996 + 2 x 1996 + 3 x 1996 + 4 x 1996

= (1 + 2 + 3 + 4) x 1996

= 10 x 1996

= 19960

b, 2 x 3 x 4 x 8 x 50 x 25 x 125

= 3 x 2 x 4 x 50 x 8 x 25 x 125

= 3 x (2 x 50) x (4 x 25) x (8 x 125)

= 30 000 000.

c, Ta nhận thấy :

45 x 128 – 90 x 64 = 45 x (2 x 64) – 90 x 64

= (45 x 2) x 64 – 90 x 64

= 90 x 64 – 90 = 0

Trong 1 tích có 1 thừa số bằng 0. Vậy tích đó bằng 0, tức là :

(45 x 46 + 47 x 48) x (51 x 52 – 49 x 48) x (45 x 128 – 90 x 64) x (1995 x 1996 + 1997 x 1998) = 0

2193: {[( 2223 - 18x): 135] + 123} + 1996 = 2013 

____ _______________________           = 2013 - 1996 = 17

[( 2223 - 18x) : 135] +123  = 2193: 17 = 129

(2223 - 18x) : 135 = 129 - 123 = 3

2223 - 18x = 135.3 = 405

18x = 2223 - 405 = 1818

x = 1818: 18 = 101

Vậy x = 101

                              tíc nha!

tim x

 2193 : {[( 2223 -18x ) : 135 ] +123} + 1996 = 2013

2193 : [( 2223 - 18x ) : 135] +123 = 17

2193 : (2223 - 18x ) : 135 = 140

2193: (2223 - 18x ) = 18900

2223 - 18x = ???

chắc là mình làm sai rồi