a) 9 -25 = (7 – x ) – (25 +7) b) -x – (-22) =55 c)| x – 2 |+ 7= 7 d)-2 x -(-25) = 45 -x 13/10/2021 Bởi Alice a) 9 -25 = (7 – x ) – (25 +7) b) -x – (-22) =55 c)| x – 2 |+ 7= 7 d)-2 x -(-25) = 45 -x
`a) 9 -25 = (7 – x ) – (25 +7)` ` -16 = 7 – x – 25 -7` ` -16 = – x – 25 ` ` x = – 25 +16` `x=-9` `b) -x – (-22) =55 ` ` -x +22 =55 ` ` -x =55 -22` `-x=33` `x=-33` `c)| x – 2 |+ 7= 7` `| x – 2 |= 7-7` `|x-2|=0` `x-2=0` `x=2` `d)-2 x -(-25) = 45 -x` `-2 x +25 = 45 -x` `-2 x +x = 45 -25` `-x=20` `x=-20` Bình luận
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`a) 9 -25 = (7 – x ) – (25 +7)`
` -16 = 7 – x – 25 -7`
` -16 = – x – 25 `
` x = – 25 +16`
`x=-9`
`b) -x – (-22) =55 `
` -x +22 =55 `
` -x =55 -22`
`-x=33`
`x=-33`
`c)| x – 2 |+ 7= 7`
`| x – 2 |= 7-7`
`|x-2|=0`
`x-2=0`
`x=2`
`d)-2 x -(-25) = 45 -x`
`-2 x +25 = 45 -x`
`-2 x +x = 45 -25`
`-x=20`
`x=-20`