Những câu hỏi liên quan
Hank Pham
Xem chi tiết
Huỳnh Ngân
Xem chi tiết
Aki Tsuki
26 tháng 4 2018 lúc 20:37

heoheo lần sau bạn đánh = kí hiệu đi :(((

a/ \(\dfrac{x}{3}+\dfrac{2x-1}{6}=\dfrac{1}{2}\)

\(\Leftrightarrow2x+2x-1=3\)

<=> 4x = 4 <=> x = 1

Vậy x = 1

b/ \(\dfrac{3x+1}{2}+\dfrac{x-1}{3}=\dfrac{x-9}{6}\)

\(\Leftrightarrow3\left(3x+1\right)+2\left(x-1\right)=x-9\)

\(\Leftrightarrow9x+3+2x-2=x-9\)

\(\Leftrightarrow10x=-10\Leftrightarrow x=-1\)

Vậy pt có nghiệm x = -1

c/ \(\dfrac{x-1}{x-2}=\dfrac{x+3}{x+2}\) ĐKXĐ: \(x\ne\pm2\)

<=> \(\left(x-1\right)\left(x+2\right)=\left(x+3\right)\left(x-2\right)\)

\(\Leftrightarrow x^2+2x-x-2=x^2-2x+3x-6\)

\(\Leftrightarrow0x=-4\left(voly\right)\)

Vậy pt vô nghiệm

d/ \(\dfrac{3x-1}{3x+1}+\dfrac{x-3}{x+3}=2\) ĐKXĐ: \(\left\{{}\begin{matrix}x\ne-3\\x\ne-\dfrac{1}{3}\end{matrix}\right.\)

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

=> (3x-1)(x+3) + (x-3)(3x+1) = 2(3x+1)(x+3)

\(\Leftrightarrow3x^2+8x-3+3x^2-8x-3=6x^2+20x+6\)

\(\Leftrightarrow-20x=12\Leftrightarrow x=-\dfrac{3}{5}\left(tm\right)\)

Vậy pt có nghiệm x=....

e/ như ý d

Nguyễn tối cao
Xem chi tiết
Phan Nghĩa
6 tháng 8 2020 lúc 15:11

\(\frac{5}{6}=\frac{x-1}{x}\left(đk:x\ne0\right)\)

\(< =>5x=6\left(x-1\right)< =>5x=6x-6\)

\(< =>6x-5x=6< =>x=6\left(tmđk\right)\)

\(\frac{1}{2}=\frac{x+1}{3x}\left(đk:x\ne0\right)\)

\(< =>3x=2\left(x+1\right)< =>3x=2x+2\)

\(< =>3x-2x=2< =>x=2\left(tmđk\right)\)

\(\frac{3}{x+2}=\frac{5}{2x+1}\left(đk:x\ne-2;-\frac{1}{2}\right)\)

\(< =>3\left(2x+1\right)=5\left(x+2\right)< =>6x+3=5x+10\)

\(< =>6x-5x=10-3< =>x=7\left(tmđk\right)\)

\(\frac{5}{8x-2}=-\frac{4}{7-x}\left(đk:x\ne\frac{1}{4};7\right)\)

\(< =>\frac{5}{8x-2}=\frac{4}{x-7}< =>5\left(x-7\right)=4\left(8x-2\right)\)

\(< =>5x-35=32x-8< =>32x-5x=-35+8\)

\(< =>27x=-27< =>x=-1\)

Khách vãng lai đã xóa
Phan Nghĩa
6 tháng 8 2020 lúc 15:19

\(\frac{4}{3}=\frac{2x-1}{3}< =>4.3=\left(2x-1\right).3\)

\(< =>12=6x-3< =>6x=12+3\)

\(< =>6x=15< =>x=\frac{15}{6}=\frac{5}{2}\)

\(\frac{2x-1}{3}=\frac{3x+1}{4}< =>4\left(2x-1\right)=3\left(3x+1\right)\)

\(< =>8x-4=9x+3< =>9x-8x=-4-3\)

\(< =>9x-8x=-7< =>x=-7\)

\(\frac{4}{x+2}=\frac{7}{3x+1}\left(đk:x\ne-2;-\frac{1}{3}\right)\)

\(< =>4\left(3x+1\right)=7\left(x+2\right)< =>12x+4=7x+14\)

\(< =>12x-7x=14-4< =>5x=10\)

\(< =>x=\frac{10}{5}=2\left(tmđk\right)\)

\(-\frac{3}{x+1}=\frac{4}{2-2x}\left(đk:x\ne-1;1\right)\)

\(< =>-3\left(2-2x\right)=4\left(x+1\right)< =>-6+6x=4x+4\)

\(< =>6x-4x=4+6< =>2x=10\)

\(< =>x=\frac{10}{2}=5\left(tmđk\right)\)

\(\frac{x+1}{3}=\frac{3}{x+1}\left(đk:x\ne-1\right)\)

\(< =>\left(x+1\right)\left(x+1\right)=3.3\)

\(< =>x^2+2x+1=9< =>x^2+2x+1-9=0\)

\(< =>x^2+2x-8=0< =>x^2-2x+4x-8=0\)

\(< =>x\left(x-2\right)+4\left(x-2\right)=0< =>\left(x+4\right)\left(x-2\right)=0\)

\(< =>\orbr{\begin{cases}x+4=0\\x-2=0\end{cases}< =>\orbr{\begin{cases}x=-4\\x=2\end{cases}}}\left(tmđk\right)\)

Khách vãng lai đã xóa
ミ★Ƙαї★彡
6 tháng 8 2020 lúc 17:02

a, \(\frac{5}{6}=\frac{x-1}{x}\Leftrightarrow5x=6x-6\Leftrightarrow-x=-6\Leftrightarrow x=6\)

b, \(\frac{1}{2}=\frac{x+1}{3x}\Leftrightarrow3x=2x+2\Leftrightarrow x=2\)

c, \(\frac{3}{x+2}=\frac{5}{2x+1}\)ĐKXĐ : \(x\ne-2;-\frac{1}{2}\)

\(\Leftrightarrow6x+3=5x+10\Leftrightarrow x=7\)

Khách vãng lai đã xóa
Pinky mộng hường 123
Xem chi tiết
阮草~๖ۣۜDαɾƙ
1 tháng 9 2018 lúc 12:00

Bn viết lại đề bài rõ hơn được ko?

MinhPhu
7 tháng 4 2021 lúc 11:07

6\85/7

Khách vãng lai đã xóa
Mai Đức Hùng
Xem chi tiết
Nguyễn Lê Phước Thịnh
13 tháng 4 2023 lúc 23:31

\(M=\left(\dfrac{x-x^2}{\left(x-1\right)^2}+\dfrac{1}{1+x}-\dfrac{x}{x-1}\right)\cdot\left(\dfrac{3x-1}{x}+\dfrac{1}{x+1}-1\right)\)

\(=\left(\dfrac{-x}{x-1}-\dfrac{x}{x-1}+\dfrac{1}{x+1}\right)\cdot\dfrac{\left(3x-1\right)\left(x+1\right)+x-x\left(x+1\right)}{x\left(x+1\right)}\)

\(=\dfrac{-2x\left(x+1\right)+x-1}{\left(x-1\right)\left(x+1\right)}\cdot\dfrac{3x^2+2x-1+x-x^2-x}{x\left(x+1\right)}\)

\(=\dfrac{-2x^2-2x+x-1}{\left(x-1\right)\left(x+1\right)}\cdot\dfrac{2x^2+2x-1}{x\left(x+1\right)}\)

\(=\dfrac{-2x^2-x-1}{\left(x-1\right)\left(x+1\right)}\cdot\dfrac{2x^2+2x-1}{x\left(x+1\right)}\)

\(=\dfrac{\left(-2x^2-x-1\right)\left(2x^2+2x-1\right)}{x\left(x+1\right)^2\cdot\left(x-1\right)}\)

Phát
Xem chi tiết
Phước Lộc
3 tháng 1 2023 lúc 17:34

\(\left(1-\dfrac{1}{2}\right)\times\left(1-\dfrac{1}{2}\right)\times\left(1-\dfrac{1}{3}\right)\times\left(1-\dfrac{1}{4}\right)\times\left(1-\dfrac{1}{5}\right)\)

\(=\dfrac{1}{2}\times\dfrac{1}{2}\times\dfrac{2}{3}\times\dfrac{3}{4}\times\dfrac{4}{5}\)

\(=\dfrac{1}{2}\times\dfrac{1}{5}\)

\(=\dfrac{1}{10}\)

Mai Nhật Huy
Xem chi tiết
Đỗ Tuệ Lâm
24 tháng 2 2022 lúc 11:22

(x-1)(2x^2-8)=0

\(\Leftrightarrow\left(x-1\right)\left(2x^2-8\right)=0\\ \left(2x^3-8x-2x^2+8\right)=0\)

\(\Leftrightarrow2x\left(x-1\right)-8\left(x-1\right)=0\)

\(\Leftrightarrow x=1;x=\dfrac{8}{2}\)

3x^2-8x+5=0

áp dụng công thức bậc 2 ta có:

\(x=\dfrac{-\left(-8\right)\pm\sqrt{\left(-8\right)^2-4.3.5}}{2.3}\)

\(\Rightarrow x=\dfrac{5}{3};x=1\)

Đỗ Tuệ Lâm
24 tháng 2 2022 lúc 11:23

(7x-1).2x-7x+1=0

\(\Leftrightarrow\left(7x-1\right)\left(2x-1\right)=0\)

\(\Leftrightarrow x=\dfrac{1}{7};x=\dfrac{1}{2}\)

Nguyễn Lê Phước Thịnh
24 tháng 2 2022 lúc 14:05

d: \(\Leftrightarrow\left(4x+2\right)\left(x-1\right)-\dfrac{1}{2}x\left(x-1\right)=0\)

\(\Leftrightarrow\left(x-1\right)\left(4x+2-\dfrac{1}{2}x\right)=0\)

\(\Leftrightarrow\left(x-1\right)\left(-\dfrac{7}{2}x+2\right)=0\)

=>x=1 hoặc x=4/7

e: \(\Leftrightarrow2\left(5x-2\right)=3\left(5-3x\right)\)

=>10x-4=15-9x

=>19x=19

hay x=1

f: \(\Leftrightarrow\dfrac{2x-1}{x-1}+1=\dfrac{1}{x-1}\)

=>2x-1+x-1=1

=>3x-2=1

hay x=1(loại)

g: =>1+3x-6=3-x

=>3x-5-3+x=0

=>4x-8=0

=>x=2(loại)

nood
Xem chi tiết
Nguyễn Lê Phước Thịnh
2 tháng 3 2023 lúc 12:12

a: =>(x-2)(3x+1)-(x-2)(x+2)=0

=>(x-2)(3x+1-x-2)=0

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

=>x=1/2 hoặc x=2

b: =>3(x-1)+4(x+1)=6(x-1)

=>3x-3+4x+4=6x-6

=>7x+1=6x-6

=>x=-7

c: =>x(x-3)-(x+2)(x+3)+16=0

=>x^2-3x-x^2-5x-6+16=0

=>10-8x=0

=>x=5/4

Đăng Nguyễn
Xem chi tiết
Na LI Mi
Xem chi tiết
Nguyễn Lê Phước Thịnh
4 tháng 6 2022 lúc 22:44

c: \(\dfrac{3x+5}{x^2-5x}+\dfrac{25-x}{25-5x}\)

\(=\dfrac{3x+5}{x\left(x-5\right)}+\dfrac{x-25}{5\left(x-5\right)}\)

\(=\dfrac{15x+25+x^2-25x}{5x\left(x-5\right)}=\dfrac{x^2-10x+25}{5x\left(x-5\right)}=\dfrac{x-5}{5x}\)

e: \(\dfrac{4x^2-3x+17}{x^3-1}+\dfrac{2x-1}{x^2+x+1}+\dfrac{6}{1-x}\)

\(=\dfrac{4x^2-3x+17+\left(2x-1\right)\left(x-1\right)-6x^2-6x-6}{\left(x-1\right)\left(x^2+x+1\right)}\)

\(=\dfrac{-2x^2-9x+11+2x^2-3x+1}{\left(x-1\right)\left(x^2+x+1\right)}\)

\(=\dfrac{-12\left(x-1\right)}{\left(x-1\right)\left(x^2+x+1\right)}=\dfrac{-12}{x^2+x+1}\)