25%x + 7,5x = -21
Tìm x, biết : 7,5x : (9- hỗn số 6 13/21) = hỗn số 2 12/25
7,5x:(9-6+13/21)=2+13//25
.tìm x:
\(7,5x:\left(9-6\frac{13}{21}\right)=2\frac{13}{25}\)
\(7,5x:\left(9-\frac{139}{21}\right)=\frac{63}{25}\)
\(7,5x:\left(\frac{189}{21}-\frac{139}{21}\right)=\frac{63}{25}\)
\(7,5x:\left(\frac{50}{21}\right)=\frac{63}{25}\)
\(7,5x=\frac{63}{25}.\frac{50}{21}\)
\(7,5x=6\)
\(x=6:7,5\)
\(x=\frac{4}{5}\)
vậy \(x=\frac{4}{5}\)
k mk nha vì mk đang âm điểm
Tìm x biết: a) 7,5x : \(\left(9-6\frac{13}{21}\right)\)= \(2\frac{14}{25}\)
7,5x:\(\frac{50}{21}\)=\(\frac{64}{25}\)
7,5x = \(\frac{64}{25}.\frac{50}{21}\)
7,5x = \(\frac{128}{21}\)
x = \(\frac{128}{21}:7,5\)
x = \(\frac{256}{315}\)
7,5x:\(\left[9-6\frac{13}{21}\right]=2\frac{13}{25}\)
\(7,5x:\left[9-6\frac{13}{21}\right]=2\frac{13}{25}\)
\(\Leftrightarrow7,5x:\left[9-\frac{139}{21}\right]=\frac{63}{25}\)
\(\Leftrightarrow7,5x:\frac{50}{21}=\frac{63}{25}\)
\(\Leftrightarrow7,5x=\frac{63}{25}.\frac{50}{21}\)
\(\Leftrightarrow7,5x=6\)
\(\Leftrightarrow x=6:7,5\)
\(\Leftrightarrow x=\frac{4}{5}=0,8\)
(Chúc bạn học tốt và tíck cho mìk vs nha!)
Tìm x thuộc N, biết:
7,5x : (9- hỗn số 6 13/21)=7. (3/5)^2
\(7,5x:\left(9-6\dfrac{13}{21}\right)=7.\left(\dfrac{3}{5}\right)^2\\ 7,5x:\left(9-\dfrac{139}{21}\right)=7.\dfrac{9}{25}\\ 7,5x:\left(\dfrac{189}{21}-\dfrac{139}{21}\right)=\dfrac{63}{25}\\ 7,5x:\dfrac{50}{21}=\dfrac{63}{25}\\ 7,5x=\dfrac{63}{25}.\dfrac{50}{21}\\ 7,5x=\dfrac{3150}{525}\\ 7,5x=\dfrac{207}{35}\\ \dfrac{15}{2}x=\dfrac{207}{35}\\ x=\dfrac{207}{35}:\dfrac{15}{2}\\ x=\dfrac{207}{35}.\dfrac{2}{15}\\ x=\dfrac{414}{525}\\ x=\dfrac{138}{175}\)
tìm x biết:
a,\(7,5x:\left(9-6\frac{13}{21}\right)=2\frac{13}{25}\)
b,\(\frac{\left(1,16-x\right)\cdot5,25}{\left(10\frac{5}{9}-7\frac{1}{4}\right)\cdot2\frac{2}{17}}\)=75%
tìm x
7,5x:(8-118/21)=43/15
3(x-1/2)-2(x+1)=1,25x-1
a) \(7,5.x:\left(8-\frac{118}{21}\right)=\frac{43}{15}\)
\(\frac{15}{2}.x:\frac{50}{21}=\frac{43}{15}\)
\(\frac{15}{2}.x.\frac{21}{50}=\frac{43}{15}\)
\(\frac{63}{20}.x=\frac{43}{15}\)
\(x=\frac{43}{15}:\frac{63}{20}\)
\(x=\frac{172}{189}\)
b) \(3.\left(x-\frac{1}{2}\right)-2.\left(x+1\right)=1,25.x-1\)
\(3x-\frac{3}{2}-2x-2=\frac{5}{4}.x-1\)
\(\Rightarrow3x-2x-\frac{5}{4}x=(-1)+\frac{3}{2}+2\)
\(x.\left(3-2-\frac{5}{4}\right)=\frac{5}{2}\)
\(x.\frac{\left(-1\right)}{4}=\frac{5}{2}\)
\(x=\frac{5}{2}:\left(\frac{-1}{4}\right)\)
\(x=-10\)
Tìm x biết
a)2 \(\frac{x}{7}\) =\(\frac{75}{35}\) b)4\(\frac{3}{x}\)=\(\frac{47}{x}\)c)x\(\frac{x}{15}\)=\(\frac{112}{5}\) d)7,5x : ( 9 - 6\(\frac{13}{21}\)) =2\(\frac{13}{25}\)
\(a,2\frac{x}{7}=\frac{75}{35}\)
\(\frac{75}{35}=2\frac{5}{35}=2\frac{1}{7}\)
\(\Rightarrow x=1\)
\(b,47:4=...\left(+3\right)\)
\(\Rightarrow\left(47-3\right):4=11\)
\(\Rightarrow x=11\)
\(c,\frac{112}{5}=\frac{336}{15}=22\left(+6\right)\)
\(\Rightarrow x=22\frac{x=6}{15}\)
\(d,7,5x=\frac{75x}{100}:\left(9-6\frac{13}{21}\right)=2\frac{13}{25}\)
\(\frac{75x}{100}:\left(9-\frac{139}{21}\right)=\frac{63}{25}\)
\(\frac{75x}{100}:\frac{50}{21}=\frac{63}{25}\)
\(\Rightarrow\frac{63^3}{25^{\left(1\right)}}\cdot\frac{50^{\left(2\right)}}{21^1}=6=\frac{6}{1}\)
\(\Rightarrow\frac{6}{1}=\frac{600}{100}\)
Con d sai đề