35 x ( 50 + 49 + 1 ) 

= 35 x 100

= 3500

gửi kb cho tớ nhé 

35*50+35*49+35

=35*50+35*49+35*1

=35*(50+49+1)

=35*100

=3500

Tk nha

=35x50+35x{49+1}

=35x50+35x50

=35x{50+50}

=35x100

=3500

35 x 50 - 35 x 49 + 3

= 36 x (50 + 49) + 3

= 36 x 99 + 3

= 3564 + 3

= 3567

35 x 50 - 35 x 49 + 3

=35x(50-49)+3

=35x1+3

=35+3  

=38

35 x 50 - 35 x 49 + 3

= 35 x ( 50 - 49 ) + 3

= 35 x 1 + 3

= 35 +  3

= 38

35 × 50 + 35 × 49 + 35 = 35 x ( 50 + 49 + 1) = 35 x 100 = 3500

7)    \(\frac{x+25}{75}+\frac{x+30}{70}=\frac{x+35}{65}+\frac{x+40}{60}\)

\(\Leftrightarrow\)\(\frac{x+25}{75}+1+\frac{x+30}{70}+1=\frac{x+36}{65}+1+\frac{x+40}{60}+1\)

\(\Leftrightarrow\)\(\frac{x+100}{75}+\frac{x+100}{70}=\frac{x+100}{65}+\frac{x+100}{60}\)

\(\Leftrightarrow\)\(\left(x+100\right)\left(\frac{1}{75}+\frac{1}{70}-\frac{1}{65}-\frac{1}{60}\right)=0\)

\(\Leftrightarrow\)\(x+100=0\)            (vì 1/75 + 1/70 - 1/65 - 1/60  \(\ne\)0)

\(\Leftrightarrow\)\(x=-100\)

Vậy.....

7)    \(\frac{x+25}{75}+\frac{x+30}{70}=\frac{x+35}{65}+\frac{x+40}{60}\)

\(\Leftrightarrow\)\(\frac{x+25}{75}+1+\frac{x+30}{70}+1=\frac{x+35}{65}+1+\frac{x+40}{60}+1\)

\(\Leftrightarrow\)\(\frac{x+100}{75}+\frac{x+100}{70}=\frac{x+100}{65}+\frac{x+100}{60}\)

\(\Leftrightarrow\)\(\left(x+100\right)\left(\frac{1}{75}+\frac{1}{70}-\frac{1}{65}-\frac{1}{60}\right)=0\)

\(\Leftrightarrow\)\(x+100=0\)    (1/75 + 1/70 - 1/65 - 1/60 \(\ne\)0)

\(\Leftrightarrow\)\(x=-100\)

Vậy...

1/2×(2×x-3)+105/2=-137/2

1/2×(2×x-3)=-137/2-105/2

1/2×(2×x-3)=-242/2

2×x-3=-242/2:1/2

2×x-3=-242

2.x=(-242)+3

2.x=239

x=239:2

x=239/2

A,-12×25-25×75-25×13

=[(-12)-75-13].25

=(-100).25

-2500

B,-50/7×49/10-35/2×-10/7+ -25/3× -9/5

=(-35)-(-25)+(-13)

=-23

C,-354+265-156+125

=[(-354)-156]+(265+125)

=(-510)+277

=-233

D,-74+40-50+16-35

=(-74)+40+(-50)+16+(-35)

=[(-74)+(-35)]+[40+(-50)+16]

=(-109)+26

=-83

E,-2/3×4/5+-4/5×4/3-0,125

=-2/3.4/5+4/5.(-4/3)-0,125

=4/5.[-2/3+(-4/3)]-0,125

=4/5.(-2)-0,125

=-8/5-0,125

=(-1,6)+(-0,125)

=-1,725

a) \(x:\frac{2}{3}=150\) 

\(x=150.\frac{2}{3}\) 

\(x=100\) 

b) \(\frac{35}{9}:x=\frac{35}{6}\) 

\(x=\frac{35}{9}.\frac{6}{35}=\frac{2}{3}\) 

c,d tương tự

a )  x : 2/3 = 150                                               c ) x : 4/7 = 180

     x         =    150 x 2/3                                        x         =    180 x  4/7

     x         =       100                                             x         =            720/7

b ) 35/9 : x  = 35/6                                             d )      49/8 : x  = 49/5 

              x  =  35/9 : 35/6                                                      x  =   49/8 : 49/5

             x   =     2/3                                                              x  =   5/8        

a) x : \(\frac{2}{3}\)= 150

   x = 150 x \(\frac{2}{3}\)

   x = 100

b) \(\frac{35}{9}:x=\frac{35}{6}\)

    x = \(\frac{35}{9}\): \(\frac{35}{6}\)

x = \(\frac{2}{3}\)

c) x : 4/7 = 180

x = 180 x 4/7

x = 720/7

d) 49/8 : x = 49/5

x = 49/8 : 49/5

x = 5/8

nhớ k cho mik nha mik đang rất cần cái k của bn

9: \(\dfrac{x-49}{50}+\dfrac{x-50}{49}=\dfrac{49}{x-50}+\dfrac{50}{x-49}\)

=>x-99=0

hay x=99

7: \(\Leftrightarrow\left(\dfrac{x+25}{75}+1\right)+\left(\dfrac{x+30}{70}+1\right)=\left(\dfrac{x+35}{65}+1\right)+\left(\dfrac{x+40}{60}+1\right)\)

=>x+100=0

hay x=-100

8:

Sửa đề: \(\dfrac{99-x}{101}+\dfrac{97-x}{103}+\dfrac{95-x}{105}+\dfrac{93-x}{107}=-4\) 

\(\Leftrightarrow\left(\dfrac{99-x}{101}+1\right)+\left(\dfrac{97-x}{103}+1\right)+\left(\dfrac{95-x}{105}+1\right)+\left(\dfrac{93-x}{107}+1\right)=0\)

=>200-x=0

hay x=200

a) 37.49+49.60+3.49

(37+60+3).49

100.49

4900

b; 36. 42 - 6².5 + 63 .6²

= 36.42 - 36.5 + 63.36

= 36.(42 - 5 + 63)

= 36.100

= 3600

c; 35 x 21 + 35 x 80 - 35

= 35 x (21 + 80 -  1)

= 35 x 100

= 3500