Question

1, giải phương trình

a, 2( x - 0,5 ) + 3 = 0,25(4x - 1 )

b , 2.\(\left(x-\dfrac{1}{4}\right)-4=-6\left(-\dfrac{1}{3}x+0,5\right)+2\)

2, giải các phương trình

a, \(\dfrac{3x-2}{2}=\dfrac{1-2x}{3}\)

b, \(\dfrac{x-1}{3}+2=3-\dfrac{2x+5}{4}\)

c, \(\dfrac{x-1}{5}+x=\dfrac{x+1}{7}\)

d, 2(x - 2,5 ) = 0,25 +\(\dfrac{4x-3}{8}\)

các bạn ơi ! giúp mik với ! mai kiểm tra rồi

Answer 1

2.a)\(\dfrac{3\text{x}-2}{2}\)=\(\dfrac{1-2\text{x}}{3}\)

<=>\(\dfrac{9\text{x}-6}{6}\)=\(\dfrac{2-4\text{x}}{6}\)

<=>9x-6=2-4x

<=>9x+4x=2+6

<=>13x=8

<=>x=\(\dfrac{8}{13}\)

Answer 2

1.a)2(x-0,5)+3=0,25(4x-1)

<=>2x-1+3=x-1phần4

<=>2x-x=-1/4+1-3

<=>x=-3/4

Answer 3

a. 2( x - 0,5 ) + 3 = 0,25(4x - 1 )

(=) 2x - 1 + 3 = x - 0,25

(=) 2x - x = 1 - 3 - 0,25

(=) x = -2,25

b. 2.

(=) 2x - 2x = 0,5 + 4 -3 +2 ( vô lí )

Vậy phương trình này vô nghiệm

Answer 4

b)2(x-\(\dfrac{1}{4}\))-4=-6(-\(\dfrac{1}{3}\)x+0,5)+2

<=>2x-\(\dfrac{1}{2}\)-4=-2x-3+2

<=>2x+2x=-3+2+\(\dfrac{1}{2}\)+4

<=>4x=\(\dfrac{7}{2}\)

<=>x=\(\dfrac{7}{8}\)

Answer 5

1 .

a.2(x-0,5)+3=0,25(4x-1)

\(\Leftrightarrow\)2x-1+3=x-0,25

\(\Leftrightarrow\)2x-x=-0,25-2

\(\Leftrightarrow\)x=-2,25

Vậy .......

b.2(x-\(\dfrac{1}{4}\))-4=-6(-\(\dfrac{1}{3}\)x+0,5)+2

\(\Leftrightarrow2x-\dfrac{1}{2}-4=2x-3+2\)

\(\Leftrightarrow2x_{_{ }}-2x=-1+4+\dfrac{1}{2}\)

\(\Leftrightarrow0x=3,5\)

\(\Rightarrow\)Vô no

Vậy ........

2.

a.\(\dfrac{3x-2}{2}=\dfrac{1-2x}{3}\)

\(\Rightarrow3\left(3x-2\right)=2\left(1-2x\right)\)

\(\Leftrightarrow9x-6=3-6x\)

\(\Leftrightarrow9x+6x=3+6\)

\(\Leftrightarrow15x=9\)

\(\Leftrightarrow x=\dfrac{3}{5}\)

Vậy .......

b.\(\dfrac{x-1}{3}+2=3-\dfrac{2x+5}{4}\)

\(\Rightarrow4\left(x-1\right)+24=36-3\left(2x+5\right)\)

\(\Leftrightarrow4x-4+24=36-6x-15\)

\(\Leftrightarrow4x+6x=21-24\)

\(\Leftrightarrow10x=-3\)

\(\Leftrightarrow x=\dfrac{-3}{10}\)

Vậy ........

c.\(\dfrac{x-1}{5}+x=\dfrac{x+1}{7}\)

\(\Rightarrow7\left(x-1\right)+35x=5\left(x+1\right)\)

\(\Leftrightarrow7x-7+35x=5x+5\)

\(\Leftrightarrow42x-5x=5+7\)

\(\Leftrightarrow37x=12\)

\(\Leftrightarrow x=\dfrac{12}{37}\)

Vậy ......

d.2(x-2,5)=0,25+\(\dfrac{4x-3}{8}\)

\(\Rightarrow6\left(x-2,5\right)=2+4x-3\)

\(\Leftrightarrow6x-15=2+4x-3\)

\(\Leftrightarrow6x-4x=-1+15\)

\(\Leftrightarrow2x=14\)

\(\Leftrightarrow x=7\)

Vậy .........