\(1235\text{×}6789\text{×}\left(630-315\text{×}2\right)\)

\(=1235\text{×}6789\text{×}\left(630-630\right)\)

\(=1235\text{×}6789\text{×}0=0\)

\(\left(100+67\right)\text{×}67+\left(200-38\right)\text{×}33\)

\(=167\text{×}67+167\text{×}33\)

\(=167\text{×}\left(67+33\right)\)

\(=167\text{×}100=16700\)

\(72+36\text{×}2+24\text{×}3+18\text{×}4+12\text{×}2+168\)

\(=72+72+72+72+24+168\)

\(=\left(72\text{×}4\right)+24+168=288+24+168=480\)

a) \(1235\times6789\times\left(630-630\right)\)

\(=1235\times6789\times0\)

\(=1235\times0\)

\(=0\)

b) \(167\times67+167\times33\)

\(=167\times\left(67+33\right)\)

\(=167\times100\)

=16700

1234 x 5678 x ( 630 - 315 x 2) : 1996 

= 1234 x 5678 x (630 -630 ) : 1996 

= 1234 x5678 x 0 : 1996

= 0

o

hok tốt

Lời giải:
1,75 phút x 11+1 phút 45 giây x 2-315 giây 

=1,75 phút x 11 + 1,75 phút x 2-5,25 phút 

=1,75 phút x 11 + 1,75 phút x 2-1,75 phút x 3

=1,75 phút x (11+2-3)=1,75 phút x 10 = 17,5 phút  

e: \(\left(1+2+4+\cdots+512\right)\times\left(101\times102-101\times101-50-51\right)\)

\(=\left(1+2+4+\cdots+512\right)\times\left(101\times102-101\times101-101\right)\)

\(=\left(1+2+4+\cdots+512\right)\times101\times\left(102-101-1\right)\)

=0

d: 1996x1995-996-1000-1996x1994

=1996x(1995-1994)-1996

=1996x1-1996

=1996-1996

=0

c: 399x46+65x399-10x399-10x399

=399x(46+65-10-10)

=399x91

=36309

b: 1234x5678x(630-315x2):1996

=1234x5678x(630-630):1996

=0

   ( 50  x 315 ) : 25

= 50 : 25 x 315

= 2 x 315

= 630 

 (50 x 315) : 25

=15750 : 25

=630

Ta có: \(9,6\times327+2,4\times315:0,25+4,8\times358:\text{0,5}\)

\(=9,6\times327+9,6\times315+9,6\times358\)

\(=9,6\times\left(327+315+358\right)=9,6\times1000=9600\)

43,57 x 2,6 x ( 630 - 315 x 2 )

=43,57 x 2,6 x ( 630 - 630 )

=43,57 x 2,6 x 0

= 0

0