420+65.4=(x+175):5+30

=> 420 + 260 = ( x + 175 ) : 5 + 30

=> 680 = ( x + 175 ) : 5 + 30 <=> ( x + 175 ) : 5 + 30 = 680

=> ( x + 175 ) : 5 = 650

=> x + 175 = 3250

=> x = 3075

420+65.4=(X+175):5+30

=>420+260=(X+175):5+30

=>680=(X+175):5+30

=>680-30=(X+175):5

=>650=(X+175):5

=>650.5=X+175

=>3250=X+175

=>X=3250-175

=>X=3075

x - 4867 = (175.2050.70):25 + 24

x - 4867 = 251125:25 + 24

x - 4867 = 1004500 +24

x = 1004500 + 24 + 4867 

x = 1009391

a) 420 + 65.4 = (x+175):5+30                          b) x - 4867 = (175.2050.70):25+23

(x+175):5+30 = 420 + 65.4                                 x - 4867 = 1004523

(x+175):5+30 = 680                                            x = 999656

(x+175):5 = 650

x+175 = 3250

x = 3075

a) 420 + 65.4 = ( x + 175 ) : 5 + 30

   420 + 260 = ( x + 175 ) : 5 + 30

    680 = ( x + 175 ) : 5 + 30

    680 - 30 = ( x + 175 ) : 5

    650 = ( x + 175 ) : 5

    650 . 5 = x + 175

     3250 = x + 175

     x = 3250 - 175

     x = 3075

a) 3636:(12x-91) =36

12x-91 = 3636:36

12x-91=101

12x=101+91

12x=192

x=192:12

x=16

b) (x : 23+45).67=8911

(x : 23+45)=8911:67

(x : 23+45)=133

x:23=133-45

x:23=88

x=88.23

x=2024

c) 420+65.4 =(x+175):5+30

420+260=(x+175):5+30

680=(x+175):5+30

(x+175):5=680-30

(x+175):5=650

(x+175)=650x5

(x+175)=3250

x=3250-175

x=3075

d) (32.15):2=(x+70):14-10

480:2=(x+70):14-10

240=(x+70):14-10

(x+70):14=240+10

(x+70):14=250

(x+70)=250.14

(x+70)=3500

x=3500-70

x=3430

e)x-4867=(175.2-50.70):25+23

x-4867=(350-3500):25+23

x-4867=-3150:25+23

x-4867=-126+23

x-4867=-103

x=-103+4867

x=4764

\(a,\Rightarrow6x+70=130\Rightarrow6x=60\Rightarrow x=10\\ b,\Rightarrow240=\left(x+70\right):14-40\\ \Rightarrow\left(x+70\right):14=280\\ \Rightarrow x+70=3920\Rightarrow x=3850\\ c,\Rightarrow x-15=75\Rightarrow x=90\\ d,\Rightarrow\left(x+175\right):5=680-30=650\\ \Rightarrow x+175=3250\Rightarrow x=3075\\ e,\Rightarrow x-4867=1004523\Rightarrow x=1009390\\ f,\Rightarrow x+32-17=24\Rightarrow x=9\\ g,\Rightarrow3\left(x+1\right)=54\Rightarrow x+1=18\Rightarrow x=17\\ h,\Rightarrow19\left(35:x+3\right)=152\\ \Rightarrow35:x+3=8\Rightarrow35:x=11\Rightarrow x=\dfrac{35}{11}\)

 ( X + 175 ) : 5 + 30 =420 + 65 x 4

 ( X + 175 ) : 5 + 30 = 680

 ( X + 175 ) : 5        = 680 - 30 = 650

 ( X + 175 )             = 650 x 5 = 3250

   X                        = 3250 - 175 = 3075

( X + 175 ) : 5 + 30 = 420 + 65 x 4

( X + 175 ) : 5 + 30 = 420 + 260

( X + 175 ) : 5 + 30 = 680

( X + 175 ) : 5=680-30

( X + 175 ) : 5=650

X + 175=650x5

X + 175=3250

X=3250-175

X=3075

420 + 65 x 4 = ( x + 175 ) : 5 + 30

( x + 175 ) : 5 + 30 = 420 + 65 x 4

( x + 175 ) : 5 + 30 = 420 + 260

( x + 175 ) : 5 + 30 = 680

( x + 175 ) : 5 = 680 - 30

( x + 175 ) : 5 = 650

 x + 175 = 650 x 5 

 x + 175 = 3250

          x = 3250 - 175

          x = 3075

Bài dễ không làm. 

3075 bai de ma tinh mot ti la xong