Question

Giúp mình với!

Answer 1

bài 2

a)2x(3x-1)=0

<=>2x=0 hoặc 3x-1=0

<=>x=0 hoặc x=\(\dfrac{1}{3}\)

b)(2x-3)(4x-5)=0

<=>2x-3=0 hoặc 4x-5=0

<=>x=\(\dfrac{3}{2}\) hoặc x=\(\dfrac{5}{4}\)

c)(x²-1)(2x-1)=0

<=>(x-1)(x+1)(2x-1)=0

<=>x-1=0 hoặc x+1=0 hoặc 2x-1=0

<=>x=1 hoặc x=-1 hoặc x=\(\dfrac{1}{2}\)

d)(x²-2x+1)-4=0

<=>(x-1)²-2²=0

<=>(x-1-2)(x-1+2)=0

<=>x-1-2=0 hoặc x-1+2=0

<=>x=3 hoặc x=-1

e)(x-3)²=(x²+2x+1)

<=>(x-3)(x+3)=x²+2x+1

<=>x²-3x-3x+9=x²+2x+1

<=>x²-3x-3x-x²-2x=1-9

<=>-8x=-8

<=>x=1

Answer 2

bài 3

a)\(\dfrac{5x-2}{3}=\dfrac{5-3x}{2}\)

<=>\(\dfrac{2\left(5x-2\right)}{3.2}=\dfrac{3\left(5-3x\right)}{2.3}\)

=>10x-4=15-9x

<=>10x+9x=15+4

<=>19x=19

<=>x=1

b)\(\dfrac{10x+3}{12}=1+\dfrac{6+8x}{9}\)

<=>\(\dfrac{3\left(10x+3\right)}{12.3}=\dfrac{1.36}{1.36}+\dfrac{4\left(6+8x\right)}{9.4}\)

<=>30x+9=36+24+32x

<=>30x-32x=36+24-9

<=>-2x=51

<=>x=\(\dfrac{-51}{2}\)

c)(bạn chụp thiếu đề)

d)\(\dfrac{7x-1}{6}+2x=\dfrac{16-x}{5}\)

<=>\(\dfrac{5\left(7x-1\right)}{6.5}+\dfrac{30\left(2x\right)}{1.30}=\dfrac{6\left(16-x\right)}{5.6}\)

=>35x-5+60x=96-6x

<=>35x+60x+6x=96+5

<=>101x=101

<=>x=1

e)\(\dfrac{3x+2}{2}-\dfrac{3x+1}{6}=\dfrac{5}{3}+2x\)

<=>\(\dfrac{6\left(3x+2\right)}{2.6}-\dfrac{2\left(3x+1\right)}{6.2}=\dfrac{4.5}{4.3}+\dfrac{12.2x}{1.12}\)

=>18x+12-6x-2=20+24x

<=>18x-6x-24x=20-12+2

<=>-12x=10

<=>\(x=-\dfrac{5}{6}\)

Answer 3

câu 4

a)\(\dfrac{2}{x+1}-\dfrac{3}{x-1}=5\)

<=>\(\dfrac{2\left(x-1\right)}{\left(x+1\right)\left(x-1\right)}-\dfrac{3\left(x+1\right)}{\left(x-1\right)\left(x+1\right)}=\dfrac{5\left(x-1\right)\left(x+1\right)}{1.\left(x-1\right)\left(x+1\right)}\)

=>2x-2-3x-3=5x²+5x-5x-5

<=>2x-3x-5x²-5x+5x=-5+3+2

<=>-x-5x²=0

<=>x(-1-5x)=0

<=>x=0 hoặc -x-5x =0

<=>x=0 hoặc x=\(-\dfrac{1}{5}\)

b)(dễ quá mình ko bt lm)

 

Answer 4

bài 1

1)17-8x=11-5x

<=>-8x+5x=11-17

<=>-3=-6

<=>x=2

2)7x+12=0

<=>7x=-12

<=>x=\(-\dfrac{12}{7}\)

3)-2x+14=0

<=>-2x=-14

<=>x=7

4)3x-1=7x-11

<=>3x-7x=-11+1

<=>-10x=-10

<=>x=1

5)2x+x+12=0

<=>2x+x=-12

<=>3x=-12

<=>x=-4

6)x-5=3-x

<=>x++x=3+5

<=>2x=8

<=>x=4

7)7-3x=9-x

<=>-3x+x=9-7

<=>-2x=2

<=>x=-2

8)(bạn chụp mờ quá mình ko nhìn được)

9)11-2x=x-1

<=>-2x-x=-1-11

<=>-3x=-12

<=>x=4

10)15-8x=9-5x

<=>-8x+5x=9-15

<=>-3x=-6

<=>x=2

11)3+2x=5+2

<=>2x=5+2+3

<=>2x=10

<=>x=5

12)(bạn chụp thiếu đề rồi)