Đáp án là D

34 - (25 + 34) = x - (25 - 9)

34 - 25 - 34 = x - 16

34 - 34 - 25 = x - 16

-25 = x - 16

-25 + 16 = x

-(25 - 16) = x

-9 = x

a)x=37

b)x=-28

c)x=-48

d)x=15

34 x 1 125 -25 x 34- 34 x 100

= 38 250 - 850 - 34 000

= 37 400 - 34 000

= 3 000

~HT~

a ) x − 2 5 : 2 3 = 3 4 x − 2 5 = 3 4 . 2 3 x − 2 5 = 1 2 x = 9 10

b ) x + − 3 4 − 1 2 = 2 3 . 3 5    x + − 3 4 − 1 2 = 2 5 x + − 3 4 = 9 10 x = 33 20

c ) x − 2 7 = − 9 14 . − 4 3 x − 2 7 = 6 7 +)  x − 2 7 = 6 7 x = 8 7 +)  x − 2 7 = − 6 7    x = − 4 7

x=-8+1 phần 2

34x(25+25+25+1)

=34x 76

=2538

25 x 34 + 34 x 25 + 34 x 25 + 1

= 850 + 850 + 850 + 1

= 2551

= 850 + 850 + 850 + 1 

= 1700 + 850 + 1

= 2550 +  1

= 2551

a: =25x10=250

b: =34x6=204

a =25 x 10=250

b =34x(11-5)=34x6=204

a. 25 x 10 =250

 C2: 25 x4 + 25 x 6 = 250

b. 374 - 170 =204

 C2 : 34 x ( 11 -5 ) = 34 x 6 = 204

FGFGG

a)-2x - 3.(x - 17) = 34 - (-x + 25)

   - 2x - 3x + 51 = 34 + x - 25

   - 2x - 3x - x = -51 + 34 - 25

   - 6x             = - 42

       x              = 7

Vậy x = 7

 b)-2x-3.(x-17)=34-2(-x+25)

- 2x - 3x + 51 = 34 + 2x - 50

- 2x - 3x - 2x = - 51 + 34 - 50

         7x        =  - 67

           x        = \(-\frac{67}{7}\)

Vậy  \(x=-\frac{67}{7}\)

c)17x-(-16x-37)=2x +43

  17x + 16x + 37 = 2x + 43

  17x + 16x - 2x = -37 + 43

               31x     = 6

                   x      = \(\frac{6}{31}\) 

Vậy \(x=\frac{6}{31}\)

\(\dfrac{18\times35\times17}{34\times25\times9}=\dfrac{9\times2\times5\times7\times17}{17\times2\times5\times5\times9}=\dfrac{7}{5}\)

\(\dfrac{18\text{×}35\text{×}17}{34\text{×}25\text{×}9}\)\(=\)\(\dfrac{7}{5}\)

\(=\dfrac{7}{5}=1,4\)