`@` `\text {Ans}`

`\downarrow`

`18*15 + 35 + 15*32 + 35*49`

`= 15 (18+32) + 35(1+49)`

`= 15*50 + 35*50`

`= 50*(15+35)`

`= 50*50`

`= 2500`

=15*50+35*50

=50*50

=2500

\(18.15+35+15.32+35.4+9\)

\(=\left(18.15+15.32\right)+\left(35+35.4\right)+9\)

\(=\left[15.\left(18+32\right)\right]+\left[35.\left(1+4\right)\right]+9\)

\(=\left[15.50\right]+\left[35.5\right]+9\)

\(=750+175+9\)

\(=934\)

= 454.46875

28 . ( 85 + 35 ) - 120 . 18

= 28 . 120 - 120 . 18

= 120 . ( 28 - 18 )

= 120 . 10

= 1200

**** , xin 

  28.85+28.35-120.18

=28(85+35)-120.18

=28.120-120.18

=120(28-18)

=120.10

=1200 

\(=9\times\left(70-70\right)+2020\)

\(=0+2020=2020\)

2020

= 35 . 18 - 35 . 28

= 35 . ( 18 - 28 )

= 35 . ( -10 )

= -350

35 . 18 - 5 . 7 . 28

= 35 . 18 - 35 . 28

= 35 . (18 - 28)

= 35 . (-10)

= -350

3/17 - 5/13 - 18/35 + 14/17 + 17/-35 - 8/13

=(3/17+14/17)+(-5/13-8/13)+(-18/35+17/35)

=1+(-1)+(-1/35)

=-1/35

Chúc bn học tốt

\(\frac{3}{17}-\frac{5}{13}-\frac{18}{35}+\frac{14}{17}\)\(+\frac{17}{-35}-\frac{8}{13}\)

\(=\left(\frac{3}{17}+\frac{14}{17}\right)\)\(-\left(\frac{18}{35}-\frac{-17}{35}\right)\)\(-\left(\frac{5}{13}+\frac{8}{13}\right)\)

\(=1-1-1\)\(=0\)

35 x 18 - 9 x 70 + 100 

= 70 x 9 - 9 x 70 + 100

=         0            + 100

=        100

35 x 18 - 9 x 70 + 100

= 35 x 2 x 9 - 9 x 70 + 100

= 70 x 9 - 9 x 70 + 100

= (70 - 70) x 9 + 100

= 0 x 9 + 100

= 100

hello

35 x 18 - 9 x 70 + 135

= 630 - 630 + 135

= 0 + 135

= 135