a) \(\left|x-3\right|=5\)
\(\Leftrightarrow\left[\begin{matrix}x-3=5\\x-3=-5\end{matrix}\right.\)
\(\Leftrightarrow\left[\begin{matrix}x=5+3=8\\x=-5+3=-2\end{matrix}\right.\)
b) \(\frac{x}{28}=\frac{-4}{7}\)
\(\Leftrightarrow x=\frac{\left(-4\right)\times28}{7}=-16\)
tìm số x biết
a) \(\frac{7}{9}:\left(2+\frac{3}{4}x\right)+\frac{5}{9}=\frac{23}{27}\) b) \(\frac{-2}{3}.x+\frac{1}{5}=\frac{3}{10}\) c) \(\left|x\right|-\frac{3}{4}=\frac{5}{3}\)
Tìm x , y :
\(\frac{x+3}{y+5}=\frac{3}{5}\) va x + y = 6
\(\frac{x-7}{y-6}=\frac{7}{6}va\) x - y = -4
+) A = ( 1,11 + 0,19 - 2,6 ) : ( 2,06 + 0,54 ) - ( \(\frac{1}{2}\) + \(\frac{1}{3}\) ) : 2
+) Tìm x :
a, (1,16 - x ) . 2,25 / 10 \(\frac{5}{9}\) - 7\(\frac{1}{4}\) . 2\(\frac{2}{11}\) = 75%
b) x + 25% .x = -1,25
c) x - 75% x = \(\frac{1}{4}\)
+) Tính nhanh nếu có thể :
a) 1\(\frac{1}{2}\) - 3\(\frac{3}{4}\) b) -8\(\frac{1}{6}\) - 7\(\frac{3}{2}\) c) 0,15 - 4,8 + 1,3 d) ( 2\(\frac{1}{3}\) + 3,5 ) : (-4\(\frac{1}{6}\) + 3\(\frac{1}{7}\) ) + 7,5
e) 11\(\frac{1}{4}\) + (2\(\frac{5}{7}\) + 5\(\frac{1}{4}\) ) f) \(\frac{4}{9}\) : ( \(\frac{1}{-7}\) + 6\(\frac{5}{9}\) :(-\(\frac{1}{7}\))
Tìm x, biết
a) \(\frac{x}{4}\)= \(\frac{21}{28}\)
b) \(\frac{2x}{5}\)= \(\frac{-24}{10}\)
tìm x biết
a) \(\frac{62}{7}.x=\frac{29}{9}:\frac{3}{56}\) b) \(\frac{1}{5}:x=\frac{1}{5}-\frac{1}{7}\)
Tìm x,y thuộc Z
a) \(\frac{-5}{x}\) = \(\frac{y}{16}\) =\(\frac{-18}{72}\)
b) \(\frac{x}{3}\) =\(\frac{5}{y}\)
c)\(\frac{x}{y}\) =\(\frac{28}{35}\)
Viết tập hợp A các số nguyên x, biết rằng:
\(\frac{-28}{4}\)\(\le\) x < \(\frac{-21}{7}\)
Tìm x \(\in\) Z biết:
a) \(\frac{x}{5}\)= \(\frac{32}{80}\); \(\frac{13}{x}\)= \(\frac{26}{30}\); \(\frac{-x}{7}\)= \(\frac{22}{-77}\)
b) \(\frac{x}{9}\)= \(\frac{28}{36}\); \(\frac{-10}{x}\)=\(\frac{50}{55}\); \(\frac{23}{-x}\)=\(\frac{46}{50}\)
Tìm x,y biết :
a) \(\frac{3}{4}x+\frac{1}{5}=-\frac{1}{2}\)
b)\(-\frac{4}{5}+\left(\frac{1}{3}:y\right)=-\frac{5}{6}\)