2/7=4/y
2xy=4x7
2xy=28
y=28:2
y=14
2/7=X/21
2x21=Xx7
42=Xx7
X=42:7=6
đúng nha cho mình one **** với
Đúng 0
Bình luận (0)
Các câu hỏi tương tự
1.Tính bằng 2 cách:
a,\(\left(\frac{5}{7}+\frac{9}{7}\right)x\frac{21}{28}\) b,\(\frac{4}{5}x\frac{13}{14}+\frac{13}{14}x\frac{1}{5}\)
Tìm x:
a) (2,8x - 32) :\(\frac{2}{3}\)=90
b) 4,5 - 2x . \(1\frac{4}{7}\)=\(\frac{11}{14}\)
c) (x+ \(\frac{1}{4}-\frac{1}{3}\) ): (2+\(\frac{1}{6}-\frac{1}{4}\))=\(\frac{7}{46}\)
d)\(\frac{13}{15}-\left(\frac{13}{21}+x\right).\frac{7}{12}=\frac{7}{10}\)
Tìm y,biết:
a,\(y-\frac{1}{3}=\frac{10}{21}\div\frac{15}{28}\)
b,\(\frac{2}{7}\div y=\frac{10}{21}\times\frac{9}{14}\)
frac{1}{3}+ frac{3}{4}x frac{5}{9}frac{7}{12}-frac{5}{4}xfrac{2}{15}y+frac{1}{4}frac{7}{8}-frac{3}{8}y-frac{5}{12}frac{2}{3}-frac{1}{4}frac{12}{7}x yfrac{16}{21}frac{5}{4}: y frac{7}{12}
Đọc tiếp
\(\frac{1}{3}\)+ \(\frac{3}{4}\)x \(\frac{5}{9}\)=
\(\frac{7}{12}\)-\(\frac{5}{4}\)x\(\frac{2}{15}\)=
y+\(\frac{1}{4}\)=\(\frac{7}{8}\)-\(\frac{3}{8}\)
y-\(\frac{5}{12}\)=\(\frac{2}{3}\)-\(\frac{1}{4}\)
\(\frac{12}{7}\)x y=\(\frac{16}{21}\)
\(\frac{5}{4}\): y =\(\frac{7}{12}\)
Đúng ghi Đ, sai ghi S vào chỗ chấm:a) frac{3}{7}+frac{1}{3}xfrac{3}{7}frac{16}{21}xfrac{3}{7}frac{16}{49} ......b)frac{5}{9}+frac{1}{5}xfrac{5}{6}frac{5}{9}xfrac{1}{6}frac{13}{18} ......c)frac{13}{9}-frac{7}{9}:frac{2}{3}frac{6}{9}:frac{3}{2}1 ......d)frac{11}{8}-frac{5}{8}:frac{3}{4}frac{11}{8}-frac{5}{8}xfrac{4}{3}frac{11}{8}-frac{10}{24}frac{23}{24} ......
Đọc tiếp
Đúng ghi Đ, sai ghi S vào chỗ chấm:
a) \(\frac{3}{7}+\frac{1}{3}x\frac{3}{7}=\frac{16}{21}x\frac{3}{7}=\frac{16}{49}\) ......
b)\(\frac{5}{9}+\frac{1}{5}x\frac{5}{6}=\frac{5}{9}x\frac{1}{6}=\frac{13}{18}\) ......
c)\(\frac{13}{9}-\frac{7}{9}:\frac{2}{3}=\frac{6}{9}:\frac{3}{2}=1\) ......
d)\(\frac{11}{8}-\frac{5}{8}:\frac{3}{4}=\frac{11}{8}-\frac{5}{8}x\frac{4}{3}=\frac{11}{8}-\frac{10}{24}=\frac{23}{24}\) ......
a) frac{2}{3}x frac{4}{7};b)frac{3}{11}x 2 ;c) 4 x frac{2}{7};d) frac{8}{21}: frac{2}{3};e) frac{3}{7}x frac{7}{3};f) frac{3}{7}: frac{3}{7};g) frac{2}{3}x frac{1}{6}x frac{9}{11};h) frac{2x3x4}{2x3x4x5}.
Đọc tiếp
a) \(\frac{2}{3}\)x \(\frac{4}{7}\);
b)\(\frac{3}{11}\)x 2 ;
c) 4 x \(\frac{2}{7}\);
d) \(\frac{8}{21}\): \(\frac{2}{3}\);
e) \(\frac{3}{7}\)x \(\frac{7}{3}\);
f) \(\frac{3}{7}\): \(\frac{3}{7}\);
g) \(\frac{2}{3}\)x \(\frac{1}{6}\)x \(\frac{9}{11}\);
h) \(\frac{2x3x4}{2x3x4x5}\).
\(\frac{75}{100}+\frac{18}{21}+\frac{19}{23}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}=\)
\(4\frac{2}{5}+5\frac{6}{9}+2\frac{3}{4}+\frac{3}{5}+\frac{1}{3}+\frac{1}{4}\)
\(\frac{2}{3\cdot5}+\frac{2}{5\cdot7}+\frac{2}{7\cdot9}+.....+\frac{2}{41\cdot43}\)
Tính dằng hai cách :
\(\frac{3}{4}\)x \(\frac{1}{2}\)x 2 Cách 1 - Cách 2 :
\(\frac{5}{7}\)x \(\frac{13}{21}\)+ \(\frac{2}{7}\)x \(\frac{13}{21}\)Cách 1 - Cách 2 :
Mọi ng giải giúp mk nha. Tại học mà cô giảng không nghe nên không biết ><
tính bằng cách thuận tiện nhất
a,\(\frac{6}{7}\cdot\frac{16}{15}\cdot\frac{7}{6}\cdot\frac{21}{32}\)b, \(\frac{21}{17}\cdot\frac{13}{14}\cdot56\cdot\frac{3}{42}\) c,\(\frac{7}{4}\cdot\frac{11}{21}+\frac{11}{21}\cdot\frac{5}{4}\) d,\(\frac{23}{14}\cdot\frac{6}{14}-\frac{9}{14}\cdot\frac{6}{13}\)