720 : [ 41 - (2x - 5 )=40
720:[41-(2x+5)]=40
720:[41-(2x-5)]=40
Ta có: \(720:\left[41-\left(2.x-5\right)\right]=40\)
\(\Rightarrow41-\left(2.x-5\right)=720:40=18\)
\(\Rightarrow2.x-5=41-18=23\)
\(\Rightarrow2.x=23+5=28\)
\(\Rightarrow x=28:2=14\)
Vậy: \(x=14\)
92-x) (5x-20) =0
679;15x+364/x =17
720:(41-(2x-5) ) =40
Tìm số nguyên x :
\(720:\left[41-\left(2x+5\right)\right]=40\)
720÷[41-(2x+5)]=2²×5
\(\Leftrightarrow36-2x=36\)
=>x=0
720÷[41-(2x+5)]=2³×5
720: [41-(2x+5)]=8 x 5
720:[41-(2x+5)]=40
41-(2x+5)=720:40
41-(2x+5)=18
2x+5=41-18
2x+5=23
2x =23-5
2x =18
x =18:2
x =9
720 : [ 41 - ( 2x - 5 ) = 2^2 . 5
\(\Leftrightarrow41-2x+5=720:20=36\)
=>-2x=0
hay x=0
d) 720:[41-(2x-5)]=2³.5
720 : [41 - (2x - 5)] = 2³.5
720 : [41 - (2x - 5)] = 8.5
720 : [41 - (2x - 5)] = 40
41 - (2x - 5) = 720 : 40
41 - (2x - 5) = 18
2x - 5 = 41 - 18
2x - 5 = 23
2x = 23 + 5
2x = 28
x = 28 : 2
x = 14
\(720:\left[41-\left(2x-5\right)\right]=2^3\cdot5\)
\(\Rightarrow720:\left(41-2x+5\right)=8\cdot5\)
\(\Rightarrow720:\left(46-2x\right)=40\)
\(\Rightarrow46-2x=720:40\)
\(\Rightarrow46-2x=18\)
\(\Rightarrow2x=46-18\)
\(\Rightarrow2x=28\)
\(\Rightarrow x=28:2\)
\(\Rightarrow x=14\)
`@` `\text {Ans}`
`\downarrow`
`d)`
`720 \div [41 - (2x - 5)] = 2^3 * 5`
`=> 720 \div [41 - (2x - 5)] = 40`
`=> 41 - (2x - 5) = 720 \div 40`
`=> 41 - (2x - 5) = 18`
`=> 2x - 5 = 41 - 18`
`=> 2x - 5 = 23`
`=> 2x = 23 + 5`
`=> 2x = 28`
`=> x = 28 \div 2`
`=> x = 14`
Vậy, `x = 14.`
720 : ( 41 - ( 2x - 5 ) = 120
720 : \([\)41 - (2x - 5)\(]\)= 120
41 - (2x -5) = 720 : 120
41 - (2x -5) = 6
2x - 5 = 41 - 6
2x - 5 = 35
2x = 35 + 5
2x = 40
x = 40 : 2
x= 20