Bài 2: Tìm x, biết: A, (7x X+8):9= 4 B, 7/5-2/5xX=1 C,( 6/5:3/5+1) x X- 6x 3/2015=6×2012/2015 21/07/2021 Bởi Jasmine Bài 2: Tìm x, biết: A, (7x X+8):9= 4 B, 7/5-2/5xX=1 C,( 6/5:3/5+1) x X- 6x 3/2015=6×2012/2015
(7x+8):9=4 =>7x+8=4.9 =>7x+8=36 =>7x=36-8 =>7x=28 =>x=4 7/5-2/5x=1 =>-2/5x=7/5-1 =>-2/5x=2/5 =>x=-2/5 Bình luận
a)`(7× x+8):9= 4` `7× x+ 8 =4×9` `7× x+ 8 =36` `7× x = 36-8` `7× x = 28` ` x = 28 : 7` ` x = 4 ` Vậy` ` x=4` b) ` 7/5-2/5 × x = 1 ` ` 2/5 × x = 7/5 – 1` ` 2/5 × x = 2/5` `x = 2/5 : 2/5` ` x = 1` ` Vậy` ` x = 1` c)`( 6/5:3/5+1) × x- 6 × 3/2015=6×2012/2015` `(6/5 . 5/3+1) × x- 18/2015 = 12072/2015 ` `(2+1) × x = 12072/2015 +18/2015` `3 × x = 6` ` x = 6:3` ` x = 2` `Vậy` ` x = 2` Bình luận
(7x+8):9=4
=>7x+8=4.9
=>7x+8=36
=>7x=36-8
=>7x=28
=>x=4
7/5-2/5x=1
=>-2/5x=7/5-1
=>-2/5x=2/5
=>x=-2/5
a)`(7× x+8):9= 4`
`7× x+ 8 =4×9`
`7× x+ 8 =36`
`7× x = 36-8`
`7× x = 28`
` x = 28 : 7`
` x = 4
` Vậy` ` x=4`
b) ` 7/5-2/5 × x = 1 `
` 2/5 × x = 7/5 – 1`
` 2/5 × x = 2/5`
`x = 2/5 : 2/5`
` x = 1`
` Vậy` ` x = 1`
c)`( 6/5:3/5+1) × x- 6 × 3/2015=6×2012/2015`
`(6/5 . 5/3+1) × x- 18/2015 = 12072/2015 `
`(2+1) × x = 12072/2015 +18/2015`
`3 × x = 6`
` x = 6:3`
` x = 2`
`Vậy` ` x = 2`