\(410-\left(5.x+42.x+x.3\right)=60\)

\(\Leftrightarrow\left(5.x+42.x+3.x\right)=410-60\)

\(\Leftrightarrow5.x+42.x+3.x=350\)

\(\Leftrightarrow\left(5+42+3\right).x=350\)

\(\Leftrightarrow50x=350\)

\(\Leftrightarrow x=350:50\)

\(\Leftrightarrow x=7\)

Vậy \(x=7.\)

\(410-\left(5x+42x+3x\right)=60\) 

\(410-50x=60\)   

\(50x=410-60\)   

\(50x=350\)        

\(x=7\)

\(\Rightarrow x:\left(0,2+0,5+0,25+0,125\right)=5,7\)

\(\Rightarrow x:1,075=5,7\)

\(\Rightarrow x=5,7.1,075=6,1275\)

x:(0,2+0,5) + (0,25+0,125)=5,7

x:0,7 + 0,375 = 5,7

x:1,075 = 5,7

x=5,7 X 1,075

x=6,1275

131 . x - 942 = 2^7 . 2^3 

131 . x - 942 = 2^10

131 . x - 942 = 1024

131 . x = 1024 + 942 

131 . x = 1966

x = 1966 : 131 

x \(\approx15\)

b ) [ ( 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

A. 131.x-942=2^7.2^3

    131.x-942=1024

    131.x       =1966

       x           =1966/131

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

     (x+32-17) .2 =42

     (x+15).2       =42

      x+15           = 21

     x                 =6

\(a,\left(x+\frac{1}{2}\right)+\left(x+\frac{1}{4}\right)+\left(x+\frac{1}{8}\right)+\left(x+\frac{1}{16}\right)=1\)

\(\Leftrightarrow x+\frac{1}{2}+x+\frac{1}{4}+x+\frac{1}{8}+x+\frac{1}{16}=1\)

\(\Leftrightarrow\left(x+x+x+x\right)+\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}\right)=1\)

\(\Leftrightarrow4\times x+\frac{15}{16}=1\)

\(\Leftrightarrow4\times x=1-\frac{15}{16}\)

\(\Leftrightarrow4\times x=\frac{1}{16}\)

\(\Leftrightarrow x=\frac{1}{16}\div4\)

\(\Leftrightarrow x=\frac{1}{64}\)

\(b,x-\frac{20}{11.13}-\frac{20}{13.15}-...-\frac{20}{53.55}=\frac{3}{11}\)

\(\Leftrightarrow x-\left(\frac{20}{11.13}+\frac{20}{13.15}+...+\frac{20}{53.55}\right)=\frac{3}{11}\)

\(\Leftrightarrow x-\left[715\times\left(\frac{1}{11}-\frac{1}{13}-\frac{1}{13}+...+\frac{1}{55}\right)\right]=\frac{3}{11}\)

\(\Leftrightarrow x-\left[715\times\left(\frac{1}{11}-\frac{1}{55}\right)\right]=\frac{3}{11}\)

\(\Leftrightarrow x-\left[715\times\frac{4}{55}\right]=\frac{3}{11}\)

\(\Leftrightarrow x-52=\frac{3}{11}\)

\(\Leftrightarrow x=\frac{3}{11}+52\)

\(\Leftrightarrow x=\frac{575}{11}\)

tháng nào mà chẳng có 28 ngày

tháng 2

 \(x\div10+x\times3,9=4,8\)

\(\Rightarrow x\times\frac{1}{10}+x\times3,9=4,8\)

\(\Rightarrow x\times\left(\frac{1}{10}+3,9\right)=4,8\)

\(\Rightarrow x\times4=4,8\)

\(\Rightarrow x=4,8\div4\)

\(\Rightarrow x=1,2\)

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bạn biết câu b ko Cô nàng cự giải

x – x : 0,2 + x : 0,125 + x = 3,25

x . 1 – x . 5 + x . 8 + x . 1 = 3,25

x . ( 1 - 5 + 8 + 1 ) = 3,25

x . 5 = 3,25

x = 3,25 : 5

x = 0,65

\(=>x\times\left(1-5+8+1\right)=3,25\)

\(=>x\times5=3,25=>x=3,25:5=0,65\)