đề bài chắc là tìm x

Hổng hiểu, đề bài đâu

nhìn cũng hổng hiểu à

tìm x đó

a, 568 + 568 x 135 - 568 x 36

= 568 x ( 1 + 135 - 36)

= 568 x 100

56 800

b, 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25

=  49 x ( 17 + 37) + 54 x ( 26 + 25 )

= 49 x 54 + 54 x 51

= 54 x ( 49 + 51)

= 54 x 100

= 5 400

c,   14 x 35 x 5 + 10 x 25 x 7 + 20 x 70

 =    ( 2 x 35) x ( 7 x 5)  + ( 10 x 7) x 25 + 20 x 70

= 70 x 35 + 70 x 25 + 20 x 70

= 70 x ( 35 + 25 + 20)

= 70 x 80

= 5 600 

a) 568 + 568 x 135 - 568 x 36

= 568 x ( 1+1+135-1-36 )

=568 x 100

=5680

b) 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25

= 49 x ( 17 + 37 ) + 54 x ( 26 + 25 )

= 49 x 54 + 54 x 51

= 54 x ( 49 + 51 )

= 54 x 100

= 5400

c) 14 x 35 x 5 + 10 x 25 x 7 + 20 x 70

= 70 x 35 + 10 x 25 x 7+ 20 x 70

= 70 x 35 + 250 x 7 + 20 x 70

= 70 x 35 + 70 x 25 + 20 x 70

= 70 x (35+25+20)

= 70 x 80

= 5600

d) ( 2 x + 1 ) 2   = 49

2x + 1 = 7 hoặc 2x + 1 = -7

2x = 6 hoặc 2x = -8

x = 3 hoặc x = -4

-25 x 72 + 25 x 21 - 49 x 25

= 25 x (-72 + 21 - 49)

= 25 x (-100) 

= -2500

-25 x 72 + 25 x 21 - 49 x 25

= 25 x ( -72 ) + 25 x 21 - 49 x 25

= 25 x ( -72 + 21 - 49 )

= 25 x ( - 100 )

= -2500

-25 x 72 + 25 x 21 - 49 x 25

= 25 x (-72 + 21 - 49)

= 25 x (-100)

= -2500

mik nah nhất đó

a: \(=81\cdot51+49\cdot81=81\cdot100=8100\)

b: \(=371\left(65+25+10\right)=37100\)

a,81*51+49*153-49*72

= 81*51+49*(153-72)

=81*51+49*81

=81*(51+49)

=81*100

=8100

5 + ( x + 27 ) = 64

a) \(\Rightarrow x+27=59\Rightarrow x=32\)

b) \(\Rightarrow x-2=39\Rightarrow x=41\)

c) \(\Rightarrow x+5=-322\Rightarrow x=-327\)

d) \(\Rightarrow5x=35\Rightarrow x=7\)

e) \(\Rightarrow4\left(x-5\right)=56\Rightarrow x-5=14\Rightarrow x=19\)

f) \(\Rightarrow15+x=37\Rightarrow x=22\)

g) \(\Rightarrow7\left(13-x\right)=35\Rightarrow13-x=5\Rightarrow x=8\)

h) \(\Rightarrow10\left(x+1\right)=100\Rightarrow x+1=10\Rightarrow x=9\)

a) `123 - 27 + 27 + 13 - 123`

`= (123 - 123) + (27 - 27) + 13`

`= 0 + 0 + 13`

`= 13`

`---`

b) `175 + 25 + 13 + 15 - 175 - 25`

`= (175-175)+(25-25)+25+13`

`=0+0+25+13`

`=28`

`---`

c) \(53\times39+47\times39+53\times21+47\times21\)

\(=\text{[}\left(53+47\right)\times39]+\left[\left(53+47\right)\times21\right]\)

\(=\left(100\times39\right)+\left(100\times21\right)\)

\(=3900+2100\)

`=6000`

`---`

d) \(49\times35+49\times16-49\times61\)

`=` \(49\times\left(35+16-61\right)\)

`=` \(49\times\left(-10\right)\)

`=-490`

= 25/49 *( 21/29-7/29) +24/49 * 15/29

=25/49*14/29+ 24/49*15/29

   BẠN TỰ LÀM TIẾP NHA

  study well

\(\frac{25}{49}.\frac{21}{29}-\frac{25}{49}.\frac{7}{29}+\frac{24}{49}.\frac{15}{29}\)

\(=\frac{25}{49}.\left(\frac{21}{29}-\frac{7}{29}\right)+\frac{24}{49}.\frac{15}{29}\)

\(=\frac{25}{49}.\frac{14}{29}+\frac{24}{49}.\frac{15}{29}\)

\(=\left(\frac{25}{49}+\frac{24}{49}\right).\left(\frac{14}{29}+\frac{15}{29}\right)\)

\(=1.1=1\)