$\frac{7}{19}+y=\frac{67}{76}$
Tim số tự nhiên x biết : 67 - x = 7
76 19
a: \(\Leftrightarrow x\cdot\dfrac{1}{19}=\dfrac{67}{76}-7=-\dfrac{465}{76}\)
hay \(x=-\dfrac{465}{4}\)
Tìm số tự nhiên x biết :
\(\dfrac{67-x}{76}=\dfrac{7}{19}\)
=>67-x = 7/19 x 76
67-x=28
x=67-28
x=39
\(19(67-x)=532=>1273-19x=532=>19x=67=>x=39\)
Tìm số tự nhiên x biết 67-x/76=7/19
67-x/76 = 7/19
=> x/76 = 1266/19
=> x= 5064
Tính nhanh
a) \(\frac{31}{23}-\left(\frac{7}{32}+\frac{8}{23}\right)\)
b) \(\left(\frac{1}{3}+\frac{12}{67}+\frac{13}{41}\right)-\left(\frac{79}{67}-\frac{28}{41}\right)\)
c) \(\frac{38}{45}-\left(\frac{8}{45}-\frac{17}{51}-\frac{3}{11}\right)\)
d) \(\frac{1}{7}.\frac{1}{3}+\frac{1}{7}.\frac{-1}{3}+\frac{17}{19}\)
e) \(\frac{3}{5}.\frac{7}{9}+\frac{7}{5}.\frac{2}{9}\)
Giúp mik vs mik đag cần gấp
a) \(\frac{31}{23}-\left(\frac{7}{32}+\frac{8}{23}\right)=\frac{31}{23}-\frac{7}{32}-\frac{8}{23}=1-\frac{7}{32}=\frac{25}{32}\)
b) \(\left(\frac{1}{3}+\frac{12}{67}+\frac{13}{41}\right)-\left(\frac{79}{67}-\frac{28}{41}\right)\)
\(=\frac{1}{3}+\frac{12}{67}+\frac{13}{41}-\frac{79}{67}+\frac{28}{41}\)
\(=\frac{1}{3}-\left(\frac{79}{67}-\frac{12}{67}\right)+\left(\frac{13}{41}+\frac{28}{41}\right)\)
\(=\frac{1}{3}-1+1=\frac{1}{3}\)
d) \(\frac{1}{7}.\frac{1}{3}+\frac{1}{7}.\frac{-1}{3}+\frac{17}{19}=\frac{1}{7}.\left(\frac{1}{3}-\frac{1}{3}\right)+\frac{17}{19}=\frac{17}{19}\)
e) \(\frac{3}{5}.\frac{7}{9}+\frac{7}{5}.\frac{2}{9}=\frac{7}{5}.\left(\frac{3}{9}+\frac{2}{9}\right)=\frac{7}{5}.\frac{5}{9}=\frac{7}{9}\)
1) \(\left(\frac{1}{3}+\frac{12}{67}+\frac{13}{41}\right)-\left(\frac{79}{67}-\frac{28}{41}\right)\)
2) \(\frac{38}{45}-\left(\frac{8}{45}-\frac{17}{51}-\frac{3}{11}\right)\)
3) \(\frac{19}{24}-\left(\frac{-1}{2}+\frac{7}{24}\right)\)
4) \(\frac{-1}{8}+\frac{7}{9}+\frac{-7}{8}+\frac{6}{7}+\frac{2}{14}\)
1) = 1/3
2) = 14/11
3) = 1
4) = 7/9
1) Tính hợp lý
a)\(\frac{31}{23}-\left(\frac{7}{32}+\frac{8}{32}\right)\)
b)\(\left(\frac{1}{3}+\frac{12}{67}+\frac{13}{41}\right)-\left(\frac{79}{67}-\frac{28}{41}\right)\)
c)\(\frac{38}{45}-\left(\frac{8}{45}-\frac{17}{51}-\frac{3}{11}\right)\)
d)\(\left(\frac{17}{28}+\frac{18}{29}-\frac{19}{30}-\frac{30}{31}\right).\left(-\frac{5}{12}+\frac{1}{4}+\frac{1}{6}\right)\)
Trả lời
b)(1/3+12/67+13/41)-(79/67-28/41)
=1/3+12/67+13/41-79/67+28/41
=1/3+(12/67-79/67)+(13/41+28/41)
=1/3+(-67/67)+41/41
=1/3+(-1)+1
=1/3+0
=1/3.
c)38/45-(8/45-17/51-3/11)
=38/45-8/45+17/51+3/11
=30/45+1/3+3/11
=2/3+1/3+3/11
=3/3+3/11
=1+3/11
=1 3/11.
d)(17/28+18/29-19/30-30/31).(-5/12+1/4+1/6)
=(17/28+18/29+19/30+30/31).(-5+3+2/12)
=(17/28+18/29+19/30+30/31).0
=0.
Tính.
41 + 19 67 + 3 76 + 14
\(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{41}\\{19}\end{array}}\\\hline{\,\,\,60}\end{array}\) \(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{67}\\{\,\,3}\end{array}}\\\hline{\,\,\,70}\end{array}\) \(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{76}\\{14}\end{array}}\\\hline{\,\,\,90}\end{array}\)
1) \(19=\frac{38}{2}=\frac{76}{4}=\frac{95}{5}\)
2) \(1=\frac{3}{3}=\frac{9}{9}=\frac{1000}{1000}\)
~~ Học tốt ~~
\(19=\frac{38}{2}=\frac{76}{4}=\frac{95}{5}\)
\(1=\frac{3}{3}=\frac{9}{9}=\frac{1000}{1000}\)
\(\hept{\begin{cases}\frac{x-y}{7}+\frac{2x+y}{17}=7\\\frac{4x+y}{5}+\frac{y-7}{19}=15\end{cases}}\)