x + 5 = 14
`-3/5xx9/14-3/5xx5/14+3/5`
`=(-3/5+3/5)xx(9/14+5/14)xx3/5`
`=0xx14xx3/5`
`=0xx1xx3/5`
`=0xx3/5`
`=0`
`@Nae`
\(-\dfrac{3}{5}\times\dfrac{9}{14}-\dfrac{3}{5}\times\dfrac{5}{14}+\dfrac{3}{5}\)
\(=\dfrac{3}{5}\times\left(-\dfrac{9}{14}-\dfrac{5}{14}+1\right)\)
\(=\dfrac{3}{5}\times\left(\dfrac{-9-5+14}{14}\right)\)
\(=\dfrac{3}{5}\times\dfrac{0}{14}\)
\(=0\)
13/14 x 5/2 - 5/14 x 5/12
tính nhanh 5/14 x 2/9 + 5/14 + 5/14 x 7/9, 6/8 : 7/6 - 6/8 : 1/6
a: \(=\dfrac{5}{14}\left(\dfrac{2}{9}+\dfrac{7}{9}+1\right)=\dfrac{5}{14}\cdot2=\dfrac{5}{7}\)
b: \(=\dfrac{6}{8}\left(\dfrac{6}{7}-6\right)=\dfrac{6}{8}\cdot\dfrac{-36}{7}=\dfrac{-216}{56}=\dfrac{-27}{7}\)
17/19 x 12/15 x 19/17 (5/7 + 9/7)x 21/18
4/5 x 13/14 + 13/14 x 1/5
a: \(=\dfrac{17}{19}\cdot\dfrac{19}{17}\cdot\dfrac{4}{5}=\dfrac{4}{5}\)
b: \(=\dfrac{14}{7}\cdot\dfrac{7}{6}=2\cdot\dfrac{7}{6}=\dfrac{14}{6}=\dfrac{7}{3}\)
c: =13/14(4/5+1/5)=13/14
17/19 x 12/15 x 19/17 (5/7 + 9/7)x 21/18
4/5 x 13/14 + 13/14 x 1/5
\(\dfrac{17}{19}\times\dfrac{12}{15}\times\dfrac{19}{17}=\dfrac{12}{15}\)
\(\left(\dfrac{5}{7}+\dfrac{9}{7}\right)\times\dfrac{21}{18}=2\times\dfrac{7}{6}=\dfrac{7}{3}\)
\(\dfrac{4}{5}\times\dfrac{13}{14}+\dfrac{13}{14}\times\dfrac{1}{5}=\dfrac{13}{14}\)
17/19 x 12/15 x 19/17 (5/7 + 9/7)x 21/18
4/5 x 13/14 + 13/14 x 1/5
\(\dfrac{17}{19}\times\dfrac{12}{15}\times\dfrac{19}{17}.\\ =\dfrac{17}{19}\times\dfrac{19}{17}\times\dfrac{12}{15}.\\ =1\times\dfrac{12}{15}=\dfrac{12}{15}.\\ \left(\dfrac{5}{7}+\dfrac{9}{7}\right)\times\dfrac{21}{18}.\\ =2\times\dfrac{7}{6}=\dfrac{7}{3}.\\ \dfrac{4}{5}\times\dfrac{13}{14}+\dfrac{13}{14}\times\dfrac{1}{5}.\\ =\left(\dfrac{4}{5}+\dfrac{1}{5}\right)\times\dfrac{13}{14}.\\ =1\times\dfrac{13}{14}.\\ =\dfrac{13}{14}.\)
a) Ta có: \(\left|x-9\right|=8\)
\(\Leftrightarrow x-9=\pm8\)
\(\Leftrightarrow\orbr{\begin{cases}x-9=8\\x-9=-8\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=17\left(TM\right)\\x=1\left(TM\right)\end{cases}}\)
Vậy \(x=17\)hoặc \(x=1\)
b);c) Ta có: \(17-\left|x+5\right|=14\)
\(\Leftrightarrow\left|x+5\right|=3\)
\(\Leftrightarrow x+5=\pm3\)
\(\Leftrightarrow\orbr{\begin{cases}x+5=3\\x+5=-3\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=-2\left(TM\right)\\x=-8\left(TM\right)\end{cases}}\)
Vậy \(x=-2\)hoặc \(x=-8\)
Có thể chuyển biểu thức 10 x 5 + 4 x 5 thành biểu thức nào dưới đây
a. 14 x 25 b. 10 x 20 c. 14 x 5 54 x 5
Có thể chuyển biểu thức 10 x 5 + 4 x 5 thành biểu thức nào dưới đây
a. 14 x 25 b. 10 x 20 c. 14 x 5 54 x 5
Tìm x, biết: a) x-5/8=1/4. b) 4/7:x=-5/14=> dấu âm ở giữ phân số 5/14
a) \(x-\dfrac{5}{8}=\dfrac{1}{4}\)
\(\Rightarrow x=\dfrac{1}{4}+\dfrac{5}{8}\)
\(\Rightarrow x=\dfrac{2}{8}+\dfrac{5}{8}=\dfrac{7}{8}\)
b) \(\dfrac{4}{7}:x=-\dfrac{5}{14}\)
\(\Rightarrow x=\dfrac{4}{7}:-\dfrac{5}{14}\)
\(\Rightarrow x=-\dfrac{8}{5}\)
a) \(x-\dfrac{5}{8}=\dfrac{1}{4}\)
\(x=\dfrac{1}{4}+\dfrac{5}{8}=\dfrac{2}{8}+\dfrac{5}{8}\)
\(x=\dfrac{7}{8}\)
b) \(\dfrac{4}{7}:x=-\dfrac{5}{14}\)
\(x=\dfrac{4}{7}:\left(-\dfrac{5}{14}\right)=\dfrac{4}{7}.\left(-\dfrac{14}{5}\right)\)
\(x=-\dfrac{8}{5}\)
a] x-5/8=1/4
x = 1/4 + 5/8
X = 7/8
B] 4/7:x= -5/14
x= 4/7 : -5/14
x= -8/5
A. 2/5 + 3/5 : 3/10 x 1/2
B.5/6 - 2/3 x 13/14 + 1/14
a: \(=\dfrac{2}{5}+\dfrac{3}{5}\cdot\dfrac{10}{3}\cdot\dfrac{1}{2}=\dfrac{2}{5}+\dfrac{10}{5}\cdot\dfrac{1}{2}=\dfrac{2}{5}+1=\dfrac{7}{5}\)