42x99-21x176-35x12

=4158-3696-420

=42

42. 99- 21. 176- 35. 12

= 4158- 3696- 420

= 462- 420

= 42

42.99-21.176-35.12

=4158-3696-420

=42

(dấu . này là nhân nha)

tick mik nha ☺

a ) 42 x 99 + 42

= 42 x 99 + 42 x 1

= 42 x ( 99 + 1 )

= 42 x 100

= 4200

b ) 28 : 4 - 12 : 4

= ( 28 - 12 ) : 4

= 16 : 4

= 4

a 42 x {99+1}

  42x100=4200

b {28-12}/4 

   16/4 

    4

a) 42x99+42 = 42 x ( 99 + 1 ) = 42x100 = 4200

b) 28:4 - 12: 4 = 28 x 1/4 - 12x1/4 = 1/4 x ( 28 - 12 ) = 1/4 x 16 =4

35 x 12 + 65 x 13 

= 420 + 845

= 2500

35x12+65x13=420+845=2500

35x12+65x13

=35x12+65x12+65

=12(35+65)+65

=12.100+65

=1265

------------Hok tốt-------------

35x12x65x13

(35+65)x12+12

100x12+12

1200+12

1212

Vũ Trọng Phú sai r

35 x 12 + 65 x 13 

= 35 x 12 + 65 x ( 12 + 1 )

= 35 x 12 + 65 x 12 + 65 x 1

= 12 x ( 35 + 65 ) + 65 

= 12 x 100 + 65 

= 1200 + 65 

=1265

   35 . 12 + 65 . 13 

= 35 . 12 + 65 . (12 + 1 )

= 35 . 12 + 35 .12 + 65 

= ( 35 + 65 ) . 12 + 65 = 1200 + 65 = 1265

=35.12+65.(12+1)

=35.12+65.12+65

=(35+65).12+65

=100.12+65

=1200+65

1265

136×68+16×272= 136×68+16×2×136

                             = 136×68+32×136

                             =136×(68+32)

                             =136×100=13600

  35×12+65×13  = 35×12+65×(12+1)

                             = 35×12+65×12+65

                             =12×(35+65)+65

                             =12×100+65

                             =1200+65=1265

a) = 35 x 12 + 65 x 12 + 65 = (35 + 65) x 12+ 65 = 100 x 12 + 65 = 1200 + 65 = 1265

b)  (2 + 4 + 6 + ...+ 100) x ( 36 x 3 x 111 - 36 x 3 x 111) =  (2 + 4 + 6 + ...+ 100) x 0 = 0 

35x12+65x13=1265

(2+4+6+.....100) x(36x333-108x111)=0

Ta có

  (2 + 4 + 6 + ...+ 100) x ( 36 x 3 x 111 - 36 x 3 x 111)

=  (2 + 4 + 6 + ...+ 100) x 0

= 0 

hok tốt

Ta có:

=35x12-15x28+23/49-23/49+2010

=420-420+0+2010

=0+2010

=2010

chúc bạn học tốt