làm hộ mk vs
\(\frac{x+9}{20}=\frac{5}{x+4}\)
a)\(\left(\frac{3}{4}x-\frac{9}{16}\right)\times\left(1,5+\frac{-3}{5}\div x\right)=0\)
Giải hộ mk vs mk đng cần gấp
\(\left(\frac{3}{4}x-\frac{9}{16}\right)\cdot\left(1,5+\frac{-3}{5}:x\right)=0\\ \Rightarrow\left[{}\begin{matrix}\frac{3}{4}x-\frac{9}{16}=0\\1,5+\frac{-3}{5}:x=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}\frac{3}{4}x=\frac{9}{16}\\\frac{-3}{5}:x=-1,5\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\frac{3}{4}\\x=\frac{2}{5}\end{matrix}\right.\)
Vậy \(x\in\left\{\frac{3}{4};\frac{2}{5}\right\}\)
\(Q=\left(\frac{x^2+1}{x+1}-1\right)\left(\frac{4}{x-1}-\frac{2}{x}\right)\)
Làm lại hộ mk vs ạ
\(Q=\left(\frac{x^2+1}{x+1}-1\right)\left(\frac{4}{x-1}-\frac{2}{x}\right)=\left(\frac{x^2+1-\left(x+1\right)}{x+1}\right)\left(\frac{4x-2\left(x-1\right)}{x\left(x-1\right)}\right)\)
\(=\left(\frac{x^2+1-x-1}{x+1}\right)\left(\frac{4x-2x+2}{x\left(x-1\right)}\right)=\left(\frac{x^2-x}{x+1}\right)\left(\frac{2\left(x+1\right)}{x\left(x-1\right)}\right)=\frac{2x\left(x+1\right)\left(x-1\right)}{x\left(x-1\right)\left(x+1\right)}=2\)
Vậy Q = 2
Hình như đề là rút gọn thì phải.
Giải
\(Q=\left(\frac{x^2+1}{x+1}-1\right)\left(\frac{4}{x-1}-\frac{2}{x}\right)\)
\(=\left(\frac{x^2}{x}-1\right)\left(\frac{4}{x-1}-\frac{2}{x}\right)=\left(x-1\right)\left(\frac{4}{x-1}-\frac{2}{x}\right)\)
\(=\frac{4\left(x-1\right)}{x-1}-\frac{2\left(x-1\right)}{x}=4-\frac{2x-2}{x}\)
Tìm x
a) \(5\frac{4}{7}:x=13\)
b) \(\left(2,8x-32\right):\frac{2}{3}=-90\)
c) \(\left(1-\frac{3}{10}-x\right)=\left(\frac{19}{10}-1-\frac{2}{5}\right)+\frac{4}{5}=1\)
d) \(7x=3,2+3x\)
CÁC BẠN LÀM ƠN GIẢI HỘ MK VS MAI MK NỘP CHO CÔ RÙI HUHU
\(a,5\frac{4}{7}:x=13\Leftrightarrow x=\frac{39}{7}:13\Leftrightarrow x=\frac{39}{7}.\frac{1}{13}=\frac{3}{7}\)
\(b,\left(2,8x-32\right):\frac{2}{3}=-90\)
\(\Leftrightarrow2,8x-32=-90.\frac{2}{3}=-60\)
\(\Leftrightarrow2,8x=-60+32=-28\)
\(\Leftrightarrow x=\frac{-28}{2,8}=-10\)
d, \(7x=3,2+3x\Leftrightarrow7x-3x=3,2\Leftrightarrow4x=3,2\Leftrightarrow x=3,2:4=3,2.\frac{1}{4}=\frac{4}{5}\)
Câu c bị sai đề :\(\frac{19}{10}-1-\frac{2}{5}=\frac{1}{2}\ne1\)bạn nha.
mình lộn \(\left(\frac{19}{10}-1-\frac{2}{5}\right)+\frac{4}{5}=\frac{13}{10}\ne1\)ms đúng nha
a) \(\frac{39}{7}:x=13\)
\(x=\frac{39}{7}:13\)
\(x=\frac{3}{7}\)
b) \(2,8x-32=-90.\frac{2}{3}\)
\(2,8x-32=-60\)
\(2,8x=-60+32\)
\(2,8x=-28\)
\(x=-28:2,8\)
\(x=-10\)
c) mik nghĩ b nên xem lại đề có đúng là có 2 dấu = ko
d) \(7x-3x=3,2\)( quy tắc chuyển vế )
\(4x=3,2\)
\(x=3,2:4\)
\(x=0,8\)
tk nha
Tính
A= (\(\frac{1}{2}\)- 1) x (\(\frac{1}{3}\)- 1) x (\(\frac{1}{4}\)- 1) x ... x (\(\frac{1}{2017}\)- 1)
Làm hộ mk vs
$1+\frac{1}{2}\left(1+2\right)+\frac{1}{3}\left(1+2+3\right)+...+\frac{1}{20}\left(1+2+3+...+20\right)$
làm hộ mk vs
Tìm x biết
\(\frac{3}{5}x-1\frac{4}{9}:\left(\frac{131313}{151515}+\frac{131313}{353535}+\frac{131313}{636363}\right)=-10\)
Giúp mk vs mk đg cần gấp
\(\frac{3}{5}x-\frac{13}{9}:\left(\frac{131313}{151515}+\frac{131313}{353535}+\frac{131313}{636363}\right)=-10\)
<=> \(\frac{3}{5}x-\frac{13}{9}:\left(\frac{13}{15}+\frac{13}{35}+\frac{13}{63}\right)=-10\)
<=> \(\frac{3}{5}x-\frac{13}{9}:13:\left(\frac{1}{15}+\frac{1}{35}+\frac{1}{63}\right)=-10\)
<=> \(\frac{3}{5}x-\frac{1}{9}:\left(\frac{21}{315}+\frac{9}{315}+\frac{5}{315}\right)=-10\)
<=> \(\frac{3}{5}x-\frac{1}{9}:\frac{35}{315}=-10\)
<=> \(\frac{3}{5}x-\frac{1}{9}:\frac{1}{9}=-10\)
<=> \(\frac{3}{5}x-1=-10\)
<=> \(\frac{3}{5}x=-9\)
<=> \(x=-15\)
Vậy x = -15.
\(\frac{3}{5}x-1\frac{4}{9}:\left(\frac{131313}{151515}+\frac{131313}{353535}+\frac{131313}{636363}\right)=-10\)
\(\Leftrightarrow\frac{3}{5}x-\frac{13}{9}:\left(\frac{13}{15}+\frac{13}{35}+\frac{13}{63}=-10\right)\)
\(\Leftrightarrow\frac{3}{5}x-\frac{13}{9}:\left[\frac{13}{2}\left(\frac{2}{15}+\frac{2}{35}+\frac{2}{63}\right)\right]=-10\)
\(\Leftrightarrow\frac{3}{5}x-\frac{13}{9}:\left[\frac{13}{2}\left(\frac{2}{3.5}+\frac{2}{.57}+\frac{2}{7.9}\right)\right]=-10\)
\(\Leftrightarrow\frac{3}{5}x-\frac{13}{9}:\left[\frac{13}{2}\left(\frac{1}{3}-\frac{1}{9}\right)\right]=-10\)
\(\Leftrightarrow\frac{3}{5}x-\frac{13}{9}:\left(\frac{13}{2}.\frac{2}{9}\right)=-10\)
\(\Leftrightarrow\frac{3}{5}x-\frac{13}{9}:\frac{26}{18}=-10\)
\(\Leftrightarrow\frac{3}{5}x-1=-10\)
\(\Leftrightarrow\frac{3}{5}x=-10+1\)
\(\Leftrightarrow\frac{3}{5}x=-9\)
\(\Rightarrow x=-9:\frac{3}{5}\)
\(\Rightarrow x=-15\)
Vậy \(x=-15\)
\(\frac{x}{2}+\frac{3}{2}\sqrt{x^2-4x+4}-2\)
giúp mk vs nhanh lên hộ vs hôm nay mk nộp bài cho rùi
\(\frac{x}{2}+\frac{3}{2}\sqrt{x^2-4x+4}-2=\frac{x}{2}+\frac{3}{2}\left|x-2\right|-2\)
Với x >= 2 thì \(\frac{x}{2}+\frac{3\left(x-2\right)}{2}=\frac{3x+x-6}{2}=\frac{4x-6}{2}=2x-3\)
Với x < 2 thì \(\frac{x}{2}+\frac{3\left(2-x\right)}{2}=\frac{x+6-3x}{2}=\frac{6-2x}{2}=3-x\)
a) \(\frac{x-3}{3}\)- 1= \(\frac{x}{-4}\)
b) \(\frac{5}{8}\)- (\(x-\frac{1}{2}\)) = \(\frac{-3}{4}\)
c) \(\frac{x}{38}-\frac{1}{19}=\frac{-1}{2}\)
d) \(\frac{x-3}{-15}+\left(x-1\right)=\frac{-5}{3}\)
e) \(\frac{x-8}{-6}+\frac{1}{2}=x-2\)
g) \(\frac{-6}{8}-\left(-x+\frac{1}{2}\right)=-3\)
h) \(x-\frac{1}{4}=\frac{-2}{14}+\frac{x}{2}\)
k) \(\left(x+3\right)-\left(x+\frac{1}{4}\right)=x\)
Làm hộ mk vs Mơn trước nhé
Nhanh mk tick
a) \(\frac{x-3}{3}-1=\frac{x}{-4}\)
\(\Leftrightarrow\frac{x-3}{3}-\frac{3}{3}=\frac{x}{-4}\)
\(\Leftrightarrow\frac{x-6}{3}=\frac{x}{-4}\)
\(\Leftrightarrow-4\left(x-6\right)=3x\)
\(\Leftrightarrow-4x+24=3x\)
\(\Leftrightarrow24=3x+4x\)
\(\Leftrightarrow7x=24\)
\(\Leftrightarrow x=\frac{24}{7}\)
b) \(\frac{5}{8}-\left(x-\frac{1}{2}\right)=\frac{-3}{4}\)
\(\Leftrightarrow\frac{5}{8}-x+\frac{1}{2}=\frac{-3}{4}\)
\(\Leftrightarrow\frac{5}{8}+\frac{4}{8}-x=\frac{-3}{4}\)
\(\Leftrightarrow\frac{9}{8}-x=\frac{-3}{4}\)
\(\Leftrightarrow x=\frac{9}{8}+\frac{3}{4}\)
\(\Leftrightarrow x=\frac{15}{8}\)
c) \(\frac{x}{38}-\frac{1}{19}=\frac{-1}{2}\)
\(\Leftrightarrow\frac{x}{38}-\frac{2}{38}=\frac{-1}{2}\)
\(\Leftrightarrow\frac{x-2}{38}=\frac{-1}{2}\)
\(\Leftrightarrow2\left(x-2\right)=-38\)
\(\Leftrightarrow2x-4=-38\)
\(\Leftrightarrow2x=-38+4\)
\(\Leftrightarrow2x=-34\)
\(\Leftrightarrow x=-34\div2\)
\(\Leftrightarrow x=-17\)
\(\frac{-x}{4}=\frac{-9}{x}\)
mấy bn giải hộ mk nhé. mk tick cho.
\(\frac{-x}{4}=\frac{-9}{x}\)
\(\Rightarrow\left(-x\right).x=\left(-9\right).4\)
\(\Rightarrow-x^2=-36\)
\(\Rightarrow x^2=36\)
\(\Rightarrow\orbr{\begin{cases}x=6\\x=-6\end{cases}}\)
vậy \(x=\pm6\)