`2 / 4 xx 3 / 6 `
`= [ 2 xx 3 ] / [ 4 xx 6 ]`
`= 6 / [ 4 xx 6 ]`
`= 1 / 4`
`\frac{2}{4}` `xx` `\frac{3}{6}` `=` `\frac{6}{24}` `=` `\frac{1}{4}`
\( Tìm x:\)
\(a, \frac{5}{6}+x×\frac{3}{4}=3\)
\(b,5\frac{1}{6}-x÷\frac{3}{4}=\frac{2}{3}\)
1. Tính nhanh
\(\frac{1}{2}\)x \(\frac{2}{3}\)x \(\frac{3}{4}\)x\(\frac{4}{5}\)x \(\frac{5}{6}\)x\(\frac{6}{7}\)x \(\frac{6}{7}\)x \(\frac{7}{8}\)x\(\frac{8}{9}\text{ }\)x \(\frac{9}{10}\)
\(\frac{1}{2}\): \(\frac{3}{2}\): \(\frac{5}{4}\)\(\frac{6}{5}\):\(\frac{7}{6}\):\(\frac{8}{7}\)
*Tìm x:
a,\(X+\frac{1}{2}-\frac{3}{4}=\frac{5}{6}\) b,\(Xx\frac{1}{3}:\frac{2}{5}=\frac{4}{3}\)
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)\(\frac{11}{8}-\frac{5}{8}:\frac{3}{4}=\frac{11}{8}-\frac{5}{8}x\frac{4}{3}=\frac{11}{8}-\frac{10}{24}=\frac{23}{24}\) ......
1.\(\frac{-3}{5}.x=\frac{5}{6}\)
2.\(\frac{2}{4}:x=\frac{6}{8}\)
3.\(\frac{67}{89}.x=\frac{12}{13}\)
1) Tính A biết rằng :
A = \(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+......+\frac{1}{64}\)
2) So sánh 2 phép tính sau:
\(\frac{1+2+3+4+5+6+7}{2+3+4+5+6+7+8}\)và \(\frac{1}{2}+\frac{2}{3}+\frac{3}{4}+\frac{6}{5}+\frac{7}{6}+\frac{8}{7}\)
3) Tìm \(x\)biết:
\(\frac{x\times7}{x}=7\) \(\frac{x}{x\times6}=\frac{1}{6}\)
4) Tìm 1 phân số nếu lấy \(\frac{12}{5}\)trừ đi phân số đó rồi chia cho \(\frac{5}{7}\)thì được \(\frac{12}{5}\).
x+\(\frac{3}{4}=\frac{5}{3}\) \(\frac{7}{5}:x=3\)\(2-x=\frac{4}{7}\)\(\frac{5}{6}\)x \(x=\frac{4}{9}\)
a)Tính bằng cách thuận tiện nhất :
\(\frac{1}{2}x\frac{1}{3}+\frac{1}{3}x\frac{1}{4}+\frac{1}{4}x\frac{1}{5}+\frac{1}{5}x\frac{1}{6}\)
b) Tính :
\(\left(1-\frac{1}{2}\right)x\left(1-\frac{1}{3}\right)x\left(1-\frac{1}{4}\right)\)
a. \(\frac{4}{3}\)- \(\frac{3}{2}\): X =\(\frac{1}{6}\)
b.( X + \(\frac{2}{3}\)) : \(\frac{1}{3}\)= \(\frac{41}{3}\)
c. X x \(\frac{11}{5}\)- X x \(\frac{4}{7}\)= \(\frac{5}{7}\)
d. 11 x ( X - 6 ) = 4 x X + 11
e. ( X - 21 x 13 ) : 11 = 30
