( \(x\) . \(1,5\) \(-\) \(\dfrac{3}{7}\) ) \(:\) \(\dfrac{1}{2}\) \(=\) \(1\dfrac{1}{7}\)
giúp mk với
tí nữa mk phải đi học rồi
cảm ơn các bn nhiều
Tính một cách hợp lí
a. \(8\dfrac{5}{7}+3,15+1\dfrac{2}{7}+4,35\)
b. \(\left(4\dfrac{5}{23}-2\dfrac{2}{5}+7\dfrac{7}{13}\right)-\left(3\dfrac{5}{23}-6\dfrac{6}{13}\right)\)
c. \(-15\dfrac{1}{2}\times20,8+3,5\times9,5-15,5\times9,2+3\dfrac{1}{2}\times20\dfrac{1}{2}\)
giúp mk với , mai mk phải nộp bài rồi
cảm ơn các bn trước nha
a.
=\(\left(\dfrac{61}{7}+\dfrac{9}{7}\right)+\left(\dfrac{63}{20}+\dfrac{87}{20}\right)\)
=\(10+\dfrac{15}{2}\)
=\(\dfrac{35}{2}\)
b.
=\(\left(4\dfrac{5}{23}-3\dfrac{5}{23}\right)+\left(7\dfrac{7}{13}+6\dfrac{6}{13}\right)-2\dfrac{2}{5}\)
=\(1+14-\dfrac{12}{5}\)
=15-\(\dfrac{12}{5}\)
=\(\dfrac{63}{5}\)
Câu C khó khó mình chưa giải được !!!
(x-\(\dfrac{3}{8}\))+\(\dfrac{1}{4}\)=\(\dfrac{7}{8}\)
Giúp mk với mai phải nộp rồi
`(x-3/8) +1/4= 7/8`
`=> x-3/8 = 7/8-1/4`
`=> x-3/8 = 7/8-2/8`
`=> x-3/8 =5/8`
`=>x= 5/8 +3/8`
`=>x= 8/8=1`
a)
X x \(\dfrac{3}{4}\)+X=\(\dfrac{7}{8}\)
b)
1-(2\(\dfrac{3}{4}\)+X-1\(\dfrac{2}{3}\)):3 4/5=0
CÁC BN GIÚP MK VỚI!
a: \(x\cdot\dfrac{3}{4}+x=\dfrac{7}{8}\)
\(\Leftrightarrow x\cdot\dfrac{7}{4}=\dfrac{7}{8}\)
\(\Leftrightarrow x=\dfrac{1}{2}\)
Phải thêm bao nhiêu vào \(\dfrac{3}{4}+\dfrac{4}{3}\)để được số đối \(\dfrac{5}{6}-\dfrac{6}{5}\)?
ghi rõ cách làm ra giúp mk nha!! cảm ơn các bn nhiều!!
Giải các phương trình sau: (TM ĐK)
1) \(\dfrac{4x-3}{x-5}=\dfrac{29}{3}\)
2) \(\dfrac{2x-1}{5-3x}=2\)
3) \(\dfrac{4x-5}{x-1}=2+\dfrac{x}{x-1}\)
4) \(\dfrac{2x+5}{2x}-\dfrac{x}{x+5}=0\)
mng giúp mk bài này vs. Cảm ơn bạn nhiều
\(1,\dfrac{4x-3}{x-5}=\dfrac{29}{3}\left(ĐKXĐ:x\ne5\right)\)
\(\Rightarrow3\left(4x-3\right)=29\left(x-5\right)\)
\(\Leftrightarrow12x-9=29x-145\)
\(\Leftrightarrow12x-9-29x+145=0\)
\(\Leftrightarrow-17x+136=0\)
\(\Leftrightarrow-17x=-136\)
\(\Leftrightarrow x=8\left(tm\right)\)
Vậy \(S=\left\{8\right\}\)
\(2,\dfrac{2x-1}{5-3x}=2\left(ĐKXĐ:x\ne\dfrac{5}{3}\right)\)
\(\Rightarrow2x-1=2\left(5-3x\right)\)
\(\Leftrightarrow2x-1=10-6x\)
\(\Leftrightarrow2x-1-10+6x=0\)
\(\Leftrightarrow8x-11=0\)
\(\Leftrightarrow8x=11\)
\(\Leftrightarrow x=\dfrac{11}{8}\left(tm\right)\)
Vậy \(S=\left\{\dfrac{11}{8}\right\}\)
\(3,\dfrac{4x-5}{x-1}=2+\dfrac{x}{x-1}\left(ĐKXĐ:x\ne1\right)\)
\(\Leftrightarrow\dfrac{4x-5}{x-1}=\dfrac{2\left(x-1\right)}{x-1}+\dfrac{x}{x-1}\)
\(\Leftrightarrow\dfrac{4x-5}{x-1}=\dfrac{2x-2}{x-1}+\dfrac{x}{x-1}\)
\(\Leftrightarrow\dfrac{4x-5}{x-1}=\dfrac{3x-2}{x-1}\)
\(\Rightarrow4x-5=3x-2\)
\(\Leftrightarrow4x-5-3x+2=0\)
\(\Leftrightarrow x-3=0\)
\(\Leftrightarrow x=3\left(tm\right)\)
Vậy \(S=\left\{3\right\}\)
\(4,\dfrac{2x+5}{2x}-\dfrac{x}{x+5}=0\left(ĐKXĐ:x\ne\dfrac{1}{2};x\ne-5\right)\)
\(\Leftrightarrow\dfrac{\left(2x+5\right)\left(x+5\right)}{2x\left(x+5\right)}-\dfrac{2x^2}{2x\left(x+5\right)}=0\)
\(\Leftrightarrow\dfrac{2x^2+15x+25}{2x\left(x+5\right)}-\dfrac{2x^2}{2x\left(x+5\right)}=0\)
\(\Leftrightarrow\dfrac{15x+25}{2x\left(x+5\right)}=0\)
\(\Rightarrow15x+25=0\)
\(\Leftrightarrow15x=-25\)
\(\Leftrightarrow x=\dfrac{-5}{3}\left(tm\right)\)
Vậy \(S=\left\{\dfrac{-5}{3}\right\}\)
\(1,\dfrac{4x-3}{x-5}=\dfrac{29}{3}\)
\(\Leftrightarrow\dfrac{3\left(4x-3\right)-29\left(x-5\right)}{3\left(x-5\right)}=0\)
\(\Leftrightarrow12x-9-29x+145=0\)
\(\Leftrightarrow-17x=-136\)
\(\Leftrightarrow x=8\)
\(2,\dfrac{2x-1}{5-3x}=2\)
\(\Leftrightarrow\dfrac{2x-1-2\left(5-3x\right)}{5-3x}=0\)
\(\Leftrightarrow2x-1-10+6x=0\)
\(\Leftrightarrow8x=11\)
\(\Leftrightarrow x=\dfrac{11}{8}\)
\(3,\dfrac{4x-5}{x-1}=2+\dfrac{x}{x-1}\)
\(\Leftrightarrow\dfrac{4x-5-2\left(x-1-x\right)}{x-1}=0\)
\(\Leftrightarrow4x-5-2x+2+2x=0\)
\(\Leftrightarrow4x=3\)
\(\Leftrightarrow x=\dfrac{3}{4}\)
\(4,\dfrac{2x+5}{2x}-\dfrac{x}{x+5}=0\)
\(\Leftrightarrow\dfrac{\left(2x+5\right)\left(x+5\right)-2x^2}{2x\left(x+5\right)}=0\)
\(\Leftrightarrow2x^2+10x+5x+25-2x^2=0\)
\(\Leftrightarrow15x=-25\)
\(\Leftrightarrow x=-\dfrac{5}{3}\)
chỉ mk với các bạn mk đang cần gấp lắm
\(\dfrac{1}{2022}x\dfrac{2}{5}+\dfrac{1}{2022}x\dfrac{7}{5}-\dfrac{1}{2022}x\dfrac{8}{10}\)
cố gắng giải giúp mk nhé các bạn !!!!
\(\dfrac{1}{2022}\) \(\times\) \(\dfrac{2}{5}\) + \(\dfrac{1}{2022}\) \(\times\) \(\dfrac{7}{5}\) - \(\dfrac{1}{2022}\) \(\times\) \(\dfrac{8}{10}\)
= \(\dfrac{1}{2022}\) \(\times\) ( \(\dfrac{2}{5}\) + \(\dfrac{7}{5}\) - \(\dfrac{8}{10}\))
= \(\dfrac{1}{2022}\) \(\times\) ( \(\dfrac{9}{5}\) - \(\dfrac{4}{5}\))
= \(\dfrac{1}{2022}\) \(\times\) \(\dfrac{5}{5}\)
= \(\dfrac{1}{2022}\times1\)
= \(\dfrac{1}{2022}\)
tìm x biết:
a) \(\left|1,5.x\right|-\)\(\left|-0,6\right|=-2+\left|0,4\right|\)
b) \(\left|x+\dfrac{7}{3}\right|-\left|-\dfrac{1}{3}\right|=0\)
các bn giúp mk vs nha mk cảm ơn lắm lắm.
a: =>|3/2x|=-2+0,4+0,6=-1(vô lý)
b: =>|x+7/3|=1/3
=>x+7/3=1/3 hoặc x+7/3=-1/3
=>x=-2 hoặc x=-8/3
a,\(\dfrac{1}{3}\times\left(x-1\right)+\dfrac{2}{5}\times\left(x+1\right)=0\)
b,4x-\(\left(x+\dfrac{1}{2}\right)=2x-\left(\dfrac{1}{2}x-5\right)\)
c,\(\left(x+\dfrac{1}{2}\right)\times\left(x-\dfrac{3}{4}\right)=0\)
Các bn ơi giúp mk với chiều mk đi học rồi !!!!!!!!!!
a. \(\dfrac{1}{3}.\left(x-1\right)+\dfrac{2}{5}.\left(x+1\right)=0\)
=> \(\dfrac{1}{3}x-\dfrac{1}{3}+\dfrac{2}{5}x+\dfrac{2}{5}=0\)
=> \(\dfrac{1}{3}x+\dfrac{2}{5}x=0+\dfrac{1}{3}-\dfrac{2}{5}\)
=> \(\dfrac{11}{15}x=\dfrac{-1}{15}\)
=> \(x=\dfrac{-1}{11}\)
Đây toán 8 mà? :v
a,\(\dfrac{1}{5}x\left(x-1\right)+\dfrac{2}{5}x\left(x+1\right)=0\)
\(\Leftrightarrow5x\left(x-1\right)+6x\left(x+1\right)=0\)
\(\Leftrightarrow\left[5\left(x-1\right)+6x\left(x+1\right)\right]x=0\)
\(\Leftrightarrow\left(5x-5+6x+6\right)x=0\)
\(\Leftrightarrow\left(11+1\right)x=0\)
\(\Leftrightarrow11x+1=0;x=0\)
\(\Leftrightarrow x=-\dfrac{1}{11};x=0\)
Vậy....
Tính nhanh: \(\dfrac{1}{5}.\dfrac{4}{7}+\dfrac{3}{7}.\dfrac{1}{5}-\dfrac{1}{5}\)
CÁC BẠN GIẢI CHI TIẾT RA GIÚP MÌNH NHÉ! CẢM ƠN CÁC BẠN RẤT NHIỀU! 🤧🙏💖
`1/5 . 4/7 + 3/7 . 1/5 -1/5`
`=1/5 . 4/7 + 3/7 . 1/5 -1/5 . 1`
`=1/5 . ( 4/7+3/7-1)`
`=1/5 . ( 7/7-1)`
`= 1/5 . 0`
`=0`
\(\dfrac{1}{5}\times\dfrac{4}{7}+\dfrac{3}{7}\times\dfrac{1}{5}-\dfrac{1}{5}=\dfrac{1}{5}\times\left(\dfrac{4}{7}+\dfrac{3}{7}-1\right)=\dfrac{1}{5}\times0=0\)
= \(\dfrac{1}{5}\).(\(\dfrac{4}{7}\)+\(\dfrac{3}{7}\)+1)
= \(\dfrac{1}{5}\)+ 0
\(\dfrac{1}{5}\)