180 - ( x - 45 ) : 2 = 120

(x-45):2               =180-120

(x-45):2              =60

x-45                   =60.2

x-45                    =120

x                          =120+45

x                          =165

mjk nhé

180-(x-45):2=120

180-(x-45)=120x2

180-(x-45)=240

đề sai

180 - ( x - 45 ) : 2 = 120

( x - 45 ) : 2 = 180 - 120

( x - 45 ) : 2 = 60

x - 45 = 60 x 2

x - 45 = 120

x = 120 + 45

x = 165

Vậy x cần tìm là 165.

  L i k e mình nha !!!

180- (x - 45) : 2 =120

=> (x-45):2=180-120

=> (x-45):2=60

=> x-45=60.2

=> x-45=120

=> x=120+45

=> x=165

180 - ( x - 45 ) : 2 = 120

( x - 45 ) : 2 = 180 - 120

( x - 45 ) : 2 = 60

x - 45 = 60 x 2

x - 45 = 120

       x = 120 + 45

       x = 165

180 - (x - 45) : 2 = 120

(x - 45) : 2 = 180 - 120 = 60

x - 45 = 60 . 2 = 120

x = 120 + 45

x = 165

\(180-\left(x-45\right):2=120\)

\(\Rightarrow\left(x-45\right):2=180-120=60\)

\(\Rightarrow x-45=60\times2=120\)

\(\Rightarrow x=120+45=165\)

Vậy x= 165

=> (x - 45) : 2 = 180 - 120 = 60

=> x - 45 = 60 x 2 = 120

=> x = 120 + 45 = 165

180-(x-45)=120:2

180-(x-45)=60

       x-45=180-60

       x-45=120

       x    =120+45

       x    =165

\(780-\left(x-45\right):2=120\)

\(\Rightarrow\left(x-45\right):2=780-120\)

\(\Rightarrow\left(x-45\right):2=660\)

\(\Rightarrow x-45=660\times2\)

\(\Rightarrow x-45=1320\)

\(\Rightarrow x=1320+45\)

\(\Rightarrow x=1365\)

Vậy x = 1365

_Chúc bạn học tốt_

780 - (x - 45) : 2 = 120

=> (x - 45) : 2 = 780 - 120

=> (x - 45) : 2 = 660

=> x - 45 = 660 x 2

=> x - 45 = 1320

=> x = 1320 + 45

=> x = 1365

vậy_

\(780-\left(x-45\right):2=120\)

               \(\left(x-45\right):2=780-120\)

                    \(\left(x-45\right):2=660\)

                     \(x-45=660.2\)

                    \(x-45=1320\)

                    \(x=1320+45\)

                    \(x=1365\)

\(180-\left(x-45\right)\div2=120\)

\(\left(x-45\right)\div2=180-120\)

\(\left(x-45\right)\div2=60\)

\(x-45=60\times2\)

\(x-45=120\)

\(x=120+45\)

\(x=165\)

\(\left(2009-x\right)\div29+32=100\)

\(\left(2009-x\right)\div29=100-32\)

\(\left(2009-x\right)\div29=68\)

\(2009-x=68\times29\)

\(2009-x=1972\)

\(x=2009-1972\)

\(x=37\)

\(\left(x-2\right)\times3-270\div45=120\)

\(\left(x-2\right)\times3-6=120\)

\(\left(x-2\right)\times3=120+6\)

\(\left(x-2\right)\times3 =126\)

\(x-2=126\div3\)

\(x-2=42\)

\(x=42+2\)

\(x=44\)

\(\left(x+0,2\right)+\left(x+0,7\right)+\left(x+1,2\right)+...+\left(x+4,2\right)+\left(x+4,7\right)=65,5\)

\(\left(x+x+x+..+x+x\right)+\left(0,2+0,7+1,2+...+4,2+4,7\right)=65,5\)

\(10x+\frac{\left(0,2+4,7\right)\times10}{2}=65,5\)

\(10x+24,5=65,5\)

\(10x=65,5-24,5\)

\(10x=41\)

\(\Rightarrow x=4,1\)

mình chịu thôi!lêu...lêu...lêu

a) \(71+65.4=\left(x+140\right):x+260\)

     \(71+260=\left(x+140\right):+260\)

                \(331=\left(x+140\right):x+260\)

  \(331-260=\left(x+140\right):x\)

                  \(71=\left(x+140\right):x\)

                \(71x=x+140\)

        \(71x-x=140\)

                \(70x=140\)

\(\Rightarrow x=140:70=2\)

b) \(180-\left(x-45\right):2=120\)

                 \(\left(x-45\right):2=180-120\)

                 \(\left(x-45\right):2=60\)

                          \(x-45=60.2\)

                          \(x-45=120\)

                                \(\Rightarrow x=120+45\)

                                \(\Rightarrow x=165\)

c) \(0.48.500-2.4.40.2\)

\(=0-2.4.40.2\)

\(=0-8.80\)

\(=0-640\)

\(=-640\)

Chậc bao nhiêu người bài nào cũng làm mà chỉ có bài lớp 6 thế này mà không ai biết làm, hay thật.