Question

Giúp tớ nhanh với ạ.

Answer 1

Đề bài là Tìm x, biết

 

Answer 2

a: =>2/5x-1=-5/4

=>2/5x=-1/4

=>x=-1/4:2/5=-1/4x5/2=-5/8

b;=>9/4x=20+9+1/4=29,25

=>x=29,25:2,25=13

Answer 3

`( (2x)/5 -1) :(-5) =1/4`

`<=>(2x)/5 -1 = 1/4 * (-5) =-5/4`

`<=> (2x)/5 = -5/4 +1 =-1/4`

`=> 8x = -5`

`<=> x=-5/8`

`2 1/4 x -9 1/4 =20`

`<=> 9/4x - 37/4 =20`

`<=> 9/4x = 20+37/4 = 80/4 +37/4 = 117/4`

`=> x = 117/4 :9/4 = 13`

Vậy `x=13`

Answer 4

`a, ((2x)/5 - 1) : (-5) = 1/4`

`=> (2x)/5 - 1 = -5/4`

`=> (2x-5)/5 = -5/4`

`=> 8x - 20 = -25`

`=> 8x = -5`

`=> x = -5/8`

`b, 2 1/4 x - 9 1/4 = 20`

`9/4x = 20 + 9,25`

`9/4x = 29,25`

`=> x = 29,25 : 9/4`

`=> x = 13`

Answer 5