nhàm:

=0+91

=91                                           

ê k mìn đik

mìn chỉ cho

x+23=54                             x  * 2 =12                                 x-12=23

          x = 54-23                               x = 12 : 2                            x=23+12

          x= 31                                     x = 6                                  x=35

k mik nhé bạn hứa rồi

x + 23 = 54                    X  × 2 = 12                    x  - 12 = 23

x = 54 - 23                     X = 12 : 2                      x = 23 + 12

x = 31                            X = 6                            x = 35

167 nha!!!!!!!!!!

=13+23+34+43+54

=36+34+43+54

=70+43+54

=113+54

=167

135--65+23-(10+23)

=135+65+23-10-23

=(135+65)+(23-23)-10

=200+0-10

=190

-12+-120+-18+120

=[(-12)+(-18)]+[(-120)+120

=-30+0

=-30

a) 35-{12-[-14-2]}=35-{12+14+2}=35-28=7

b)49+54-23=49+31=80

35 - {12-[(-14) + (-2)]}

= 35 - 12 + (-14) + (-2)

= 35 - (-14) + 12 - (-2)

= 35 - (-14) + 14

= 35 - 0

= 35

23 x 2 = 46

56 - 6 = 50

12 + 34 = 45

54 : 2 = 27

ủng hộ mk nha ^_-

23 x 2 = 46

56 - 6 = 50

12 + 34 = 46

54 : 2 = 27

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

a: =6/35x39/54=13/105

b: \(=\dfrac{-5}{7}\left(\dfrac{2}{11}+\dfrac{9}{11}\right)+\dfrac{12}{7}=\dfrac{-5}{7}+\dfrac{12}{7}=1\)

cảm ơn

a, \(\dfrac{7}{15}\)+\(\dfrac{18}{54}\)
=  \(\dfrac{7}{15}\)+ \(\dfrac{1}{3}\)
=  \(\dfrac{7}{15}\)+\(\dfrac{5}{15}\)
=    \(\dfrac{12}{15}\) = \(\dfrac{4}{5}\) =0,8
b, \(\dfrac{12}{25}\)+\(\dfrac{23}{75}\)-\(\dfrac{1}{4}\)
=     \(\dfrac{59}{75}\)   -\(\dfrac{1}{4}\)
=         \(\dfrac{161}{300}\)
   

a, 7/15 + 18/54 = 4/5