18/21 +19/32 +3/21+13/32

= (18/21 + 3/21) + (19/32 + 13/32)

= 1 + 1=2

2

2

\(\frac{75}{100}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)

\(=\frac{3}{4}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)

\(=\left(\frac{3}{4}+\frac{1}{4}\right)+\left(\frac{18}{21}+\frac{3}{21}\right)+\left(\frac{19}{32}+\frac{13}{32}\right)\)

\(=1+1+1\)

\(=3\)

Học tốt #

ồ khó thế ?

Ta có:\(x.\frac{1}{5}+x.\frac{4}{5}=2\)

=>\(x.\frac{1}{5}+\frac{4}{5}=2\)

=>\(x.\frac{5}{5}=2\)

=>\(x.1=2\)

=>\(x=2:1\)

=>\(x=2\)

1. X x 1/5 + X x 4/5 = 2

   X x (1/5 + 4/5)     = 2

   X x 1                  = 2

   X                       = 2 : 1

   X                       = 2

2. 18/21 - 19/32 + 3/21 + 13/32

= (18/21 + 3/21) - (19/32 + 13/32)

= 21/21 - 32/32

= 1 - 1

= 0 

a) (-28)-(-32)=(-28)+32

b) 50-(-21)=50+21

c) (-45)-30=(-45)+(-30)

d) x-80=x+(-80)

e) 7-a=7+(-a)

g) (-25)-(-a)=(-25)+a

k cho minh nha

k cho minh nha

lần lượt là:3920

6000

5600

6100

dễ

=(7x3)/(3x23)+(4x4)/(23x4)+12/23-(16x2)/27x2)

=7/23+4/23+12/23-16/27

=23/23-16/27

=1-16/27=11/27

32 + 15 x 21

= 32 + 315

= 347

32+15x21=347

~~~hok tốt~~~

\(32+15\times21\)

\(=32+315\)

\(=347\)

_Chúc bạn học tốt_

[ ( x + 32 ) - 17 ] . 2 + 8 = 50

[ ( x + 32 ) - 17 ] . 2 = 50 - 8

[ ( x + 32 ) - 17 ] . 2 = 42

( x + 32 ) - 17 = 42 : 2 

( x + 32 ) - 17 = 21

x + 32 = 21 + 17

x + 32 = 38

x = 38 - 32

x = 6

Vậy x = 6

=))