( 2009 - x ) : 29 + 32 = 100

( 2009 - x ) : 29        = 100 - 32 

( 2009 - x ) : 29        = 68 

( 2009 - x )              = 68 . 29  

  2009 - x                = 1972

            x                = 2009 - 1972

            x                = 37

[2009 - x] : 29 =100-32

[2009-x] : 29 =68

2009-x =68x29

2009-x=1972

x=2009-1972

x=37

(2009-x):29+32=100

=>(2009-x):29=100-32

=>(2009-x):29=68

=>2009-x=68x29

=>2009-x=1972

=>x=2009-1972

=>x=37

\(\left(2009-x\right):29+32=100\\ =>\left(2009-x\right):29=100-32=68\\ =>2009-x=68.29=1972\\ =>x=2009-1972=37\)

-

\(\left(x-2\right).3-270:45=120\\ =>3\left(x-2\right)-6=120\\ =>3\left(x-2\right)=120+6=126\\ =>x-2=126:3=42\\ =>x=42+2=44\)

#)Giải :

a)\(\left(x-149\right)\div35=270\)

\(\Leftrightarrow x-149=9450\)

\(\Leftrightarrow x=9599\)

\(a,(x-149):35=270\)

\(\Leftrightarrow x-149=9450\)

\(\Leftrightarrow x=9450+149=9599\)

Vậy x = 9599

\(b,(2009-x):29+32=100\)

\(\Leftrightarrow(2009-x):29=68\)

\(\Leftrightarrow2009-x=1972\)

\(\Leftrightarrow x=2009-1972=37\)

Vậy x = 37

\(c,x+472=918\)

\(\Leftrightarrow x=918-472=446\)

Vậy x = 446

a) (x - 149) : 35 = 270

              x - 149 = 270 . 35

               x - 149 = 9450

                        x = 9450 + 149

                        x = 9599

b) (2009 - x) : 29 + 32 = 100

            (2009 - x) : 29 = 100 - 32

            (2009 - x) : 29 = 68

                     2009 - x = 68 x 29

                    2009 - x = 1972

                               x = 2009 - 1972

                               x = 37

c) x + 172 = 918

              x = 918 - 472

              x = 446

\(e,\left(x-2\right).3-270:45=120\)

\(\Rightarrow\left(x-2\right).3-6=120\)

\(\Rightarrow\left(x-2\right).3=126\)

\(\Rightarrow x-2=42\)

\(\Rightarrow x=44\)

Bài làm

a) 16 . 34 + 66 . 16 - 72 

= 16 . ( 34 + 16 ) - 72

= 16 . 80 - 72

= 1280 - 72

= 1208

b) 4,25 . 58,47 + 125  + 41,53 . 4,25

= 4,25 . ( 58,47 + 41,53 ) + 125

= 4,25 . 100 + 125

= 425 + 125

= 550

c) x : 15 + 42 = 15 + 25 . 8 

    x : 15 + 42 = 15 + 200

    x : 15 + 42 = 215

    x : 15         = 215 - 42

    x : 15         = 173

    x                = 173 . 15

    x                = 188

Vậy x = 188

~ Hai câu cuối làm nốt nha, hết thời gian cho một câu hỏi r. ~

# Học tốt #

\(180-\left(x-45\right)\div2=120\)

\(\left(x-45\right)\div2=180-120\)

\(\left(x-45\right)\div2=60\)

\(x-45=60\times2\)

\(x-45=120\)

\(x=120+45\)

\(x=165\)

\(\left(2009-x\right)\div29+32=100\)

\(\left(2009-x\right)\div29=100-32\)

\(\left(2009-x\right)\div29=68\)

\(2009-x=68\times29\)

\(2009-x=1972\)

\(x=2009-1972\)

\(x=37\)

\(\left(x-2\right)\times3-270\div45=120\)

\(\left(x-2\right)\times3-6=120\)

\(\left(x-2\right)\times3=120+6\)

\(\left(x-2\right)\times3 =126\)

\(x-2=126\div3\)

\(x-2=42\)

\(x=42+2\)

\(x=44\)

\(\left(x+0,2\right)+\left(x+0,7\right)+\left(x+1,2\right)+...+\left(x+4,2\right)+\left(x+4,7\right)=65,5\)

\(\left(x+x+x+..+x+x\right)+\left(0,2+0,7+1,2+...+4,2+4,7\right)=65,5\)

\(10x+\frac{\left(0,2+4,7\right)\times10}{2}=65,5\)

\(10x+24,5=65,5\)

\(10x=65,5-24,5\)

\(10x=41\)

\(\Rightarrow x=4,1\)

\(\left(2008-x\right):29+32=100\)

\(\Leftrightarrow\left(2008-x\right):29=68\)

\(\Leftrightarrow2008-x=1972\)

\(\Leftrightarrow x=36\)

(Tíck cho mìk vs nhá!)

( 2008 - x ) : 29 + 32 = 100

( 2008 - x ) : 29 = 100 - 32

( 2008 - x ) : 29 = 68

2008 - x = 68 x 29

2008 - x = 1972

x = 2008 - 1972

x = 36

 Vậy x = 36

\(\left(2008-x\right):29+32=100\)

\(\left(2008-x\right):29=100-32\)

\(\left(2008-x\right):29=68\)

\(2008-x=68\cdot29\)

\(2008-x=1976\)

                \(x=2008-1976\)

                \(x=32\)

( 2015 - x ) : 29 + 32 = 100

( 2015 - x ) : 29 = 100 - 32

( 2015 - x ) : 29 = 68

2015 - x = 68 x 29

2015 - x = 1972

x = 2015 - 1972

x = 43

L i k e nha các bạn !!!

(2015-x):26=100-32

(2015-x):26=68

2015-x=68x26

2015-x=1768

x=2015-1768

x=247
 

Ta co : 

(2015 - x):29+32=100

(2015-x):29       = 100 - 32

(2015-x):29       = 68

2015-x             = 68 . 29

2015-x             = 1972

x                      = 2015 - 1972

x                      =43

bài 2 tìm x

a,106- ( x+ 7) =9

x+7 = 106 - 9

x+7 = 107

x= 107 - 7

x=100

b, 2 x ( x+ 4) + 5 =65

2 x (x+4) = 65 - 5

2 x (x+4) = 60

x+4 = 60:2

x+4= 30

x= 30 - 4

x=26

c, (16x x -32) x 45=0

16 x X - 32 = 0: 45

16 x X - 32 =0

16 x X = 0 + 32

16 x X = 32

X= 32:16

X=2

d, x+4 x x = 100 : 5

X + 4 x X = 20

(1+4) x X = 20

5 x X  = 20

X= 20:5

X=4

Bài 1:

a, 24 x 66 - 24 + 36 x 24

= 24 x (66-1+36)

= 24 x 101

= 24 x 100 + 24

= 2400+24

=2424

b, 29 x 173 - 29 x 72 - 29

= 29 x (173 - 72 -1)

= 29 x 100

= 2900

c, 1+5+10+15+...+55+60

= (5+60) x 6 + 1 (có 6 cặp)

= 65 x 6 + 1

= 390 +1 =391

d, D= 1 x 2 + 2 x 3 + 3 x 4 +...+18 x 19 + 19 x 20

3D= 1 x 2 x 3+ 2 x 3 x (4-1) + 3 x 4 x (5-2) +...+ 18 x 19 x (20 - 17) + 19 x 20 x (21-18)

3D= 1 x 2 x 3 - 1 x 2 x 3 + 2 x 3 x 4 - 2 x 3 x 4 +.... + 19 x 20 x 21 - 18 x 19 x 20

3D= 19 x 20 x 21 =7980

=> D= 7980:3=2660

a) \(437\times136-437\times125\)

\(=437\times\left(136-125\right)\)

\(=437\times11\)

\(=4807\)

b) \(2009\times71+29\times2009\)

\(=2009\times\left(71+29\right)\)

\(=2009\times100\)

\(=200900\)

a) 437 x 136 - 437 x 125

= 437 x (136 - 125 )

= 437 x 11

=  4807

b) 2009 x 71 + 29 x 2009

= 2009 x ( 71 + 29 ) 

= 2009 x 100

= 200900

a) 437 x 136 - 437 x 125

  = 437 x (136 - 125)

  = 437 x 11

  = 4807

b) 2009 x 71 + 29 x 2009

   = 2009 x (71 + 29)

   =2009 x 100

   =200900

                                                  nhớ nha!