Giải phương trình `a) 1 + x/9 = 4/3 - 1/2 ` ` b) 1/6 + x/4 = 2 - x/3 `

2 câu trả lời

`a) 1+x/9 = 4/3-1/2`

`=> 1+x/9 = (4*2)/(3*2)-(1*3)/(2*3)`

`=> 1+x/9 = 8/6 - 3/6`

`=> 1+x/9 = 5/6`

`=> x/9 = 5/6-1 = 5/6-6/6`

`=> x/9 = -1/6`

`=> x = -1/6 * 9 = -1,5`

`b) 1/6+x/4=2-x/3`

`=> 1/6+x/4+x/3=2`

`=> x/4+x/3 = 2-1/6`

`=> (x*3)/(4*3) + (x*4)/(3*4) = 12/6 - 1/6`

`=> (3x)/12 + (4x)/12 = 11/6`

`=> 7x/12 = 11/6`

`=> 7x = 11/6*12 = 22`

`=> x = 22/7`

$a,1+\dfrac{x}{9}=\dfrac{4}{3}-\dfrac{1}{2}$

$⇔1+\dfrac{x}{9}=\dfrac{5}{6}$

$⇔\dfrac{x}{9}=-\dfrac{1}{6}$

$⇔6x=-9$

$⇔x=-\dfrac{3}{2}$

Vậy `S={-\frac{3}{2}}`

$b,\dfrac{1}{6}+\dfrac{x}{4}=2-\dfrac{x}{3}$

$⇔\dfrac{2}{12}+\dfrac{3x}{12}=\dfrac{24}{12}-\dfrac{4x}{12}$

$⇔2+3x=24-4x$

$⇔3x+4x=24-2$

$⇔7x=22$

$⇔x=\dfrac{22}{7}$

Vậy `S={\frac{22}{7}}`

 

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