tính
\(\frac{4\cdot5\cdot6}{3\cdot10\cdot8}\)
ghi nhớ dấu chấm là dấu nhân
Tính (theo mẫu)
Mẫu:\(\frac{5\cdot6\cdot7\cdot9}{12\cdot7\cdot27}\)=\(\frac{5\cdot6\cdot7\cdot9}{6\cdot2\cdot7\cdot9\cdot3}\)=\(\frac{5}{6}\)
a.\(\frac{3\cdot4\cdot7}{12\cdot8\cdot9}\).............................................
b.\(\frac{4\cdot5\cdot6}{12\cdot10\cdot8}\)...........................................
c.\(\frac{5\cdot6\cdot7}{12\cdot14\cdot15}\)........................................
(Lưu ý:Dấu chấm là dấu nhân)
a, \(\frac{3.4.7}{12.8.9}\)= \(\frac{3.4.7}{3.4.8.9}\)= \(\frac{7}{72}\)
b, \(\frac{4.5.6}{12.10.8}\)= \(\frac{4.5.6}{3.4.2.5.8}\)= \(\frac{1}{8}\)
c, \(\frac{5.6.7}{12.14.15}\)= \(\frac{5.6.7}{2.6.2.7.3.5}\)= \(\frac{1}{12}\)
\(\frac{1}{2\cdot3}\)+\(\frac{1}{3\cdot4}\)+\(\frac{1}{4\cdot5}\)+\(\frac{1}{5\cdot6}\)+\(\frac{1}{6\cdot7}\)+\(\frac{1}{7\cdot8}\)+\(\frac{1}{8\cdot9}\)+ \(\frac{1}{9\cdot10}\)
Tính hộ tôi [Lưu ý : dấu chấm bằng dấu nhân]
bai nay de thui
nhung bay gio mk ban
luc nao ranh mk lam
cho nha
minhpham@gmail.com
To cu tuong day kien thuc lop 6
\(=\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}+\frac{1}{7}-\frac{1}{8}+\frac{1}{8}-\frac{1}{9}+\frac{1}{9}-\frac{1}{10}=\frac{1}{2}-\frac{1}{10}=\frac{5-1}{10}=\frac{4}{10}=\frac{2}{5}\)
A=\(A=\frac{1\cdot3\cdot5+2\cdot6\cdot10+4\cdot12\cdot20+7\cdot25\cdot35}{1\cdot5\cdot7+2\cdot10\cdot19+4\cdot20\cdot28+7\cdot35\cdot49}\)
* là dấu nhân
\(a=\frac{2\cdot9\cdot8+3\cdot12\cdot10+4\cdot15\cdot12+...+98\cdot297\cdot200}{23\cdot4+3\cdot4\cdot5+4\cdot5\cdot6+...+98\cdot99\cdot100}\)
Tính a2
Tách phần lử trên ra sao cho có thể rút gọn với phần ơn dưới
tính nhanh:
\(\frac{1\cdot2\cdot3+2\cdot4\cdot6+3\cdot6\cdot9+4\cdot8\cdot12}{1\cdot3\cdot4+4\cdot6\cdot8+6\cdot9\cdot12+8\cdot12\cdot16}\)
dấu \(\cdot\)là dấu nhân nha!
=\(\frac{6\left(1+8+27+64\right)}{12\left(1+16+54+128\right)}\)
=\(\frac{6.100}{12.199}\)
=\(\frac{50}{199}\)
Tk mình với nha mọi người!!!!!
\(\frac{1x2x3+2x4x6+3x6x9+4x8x12}{1x3x4+4x6x8+6x9x12+8x12x16}\)
\(\frac{6x\left(1+8+27+64\right)}{12x\left(1+16+54+128\right)}=\frac{6x100}{12x199}=\frac{50}{199}\)
\(\frac{7}{3\cdot4}-\frac{9}{4\cdot5}+\frac{11}{5\cdot6}-\frac{13}{6\cdot7}+\frac{15}{7\cdot8}-\frac{17}{8\cdot9}+\frac{19}{9\cdot10}\)
ta có:(3+4)/4=3/(3*4)+4/(3*4) =1/4+1/3 chứng minh tương tự,cộng vế với vế, ta được kết quả là 13/30
Tính tổng:\(S=\frac{1}{1\cdot3}-\frac{1}{2\cdot4}+\frac{1}{3\cdot5}-\frac{1}{4\cdot6}+\frac{1}{5\cdot7}-\frac{1}{6\cdot8}+\frac{1}{7\cdot9}-\frac{1}{8\cdot10}\)
\(S=\left(\frac{1}{1.3}+\frac{1}{3.5}+\frac{1}{5.7}+\frac{1}{7.9}\right)-\left(\frac{1}{2.4}+\frac{1}{4.6}+\frac{1}{6.8}+\frac{1}{8.10}\right)\)
=>\(S=\frac{1}{2}.\left(\frac{2}{1.3}+\frac{2}{3.5}+\frac{2}{5.7}+\frac{2}{7.9}\right)-\frac{1}{2}.\left(\frac{2}{2.4}+\frac{2}{4.6}+\frac{2}{6.8}+\frac{2}{8.10}\right)\)
=>\(S=\frac{1}{2}.\left(1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}\right)-\frac{1}{2}.\left(\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+\frac{1}{6}-\frac{1}{8}+\frac{1}{8}-\frac{1}{10}\right)\)
=>\(S=\frac{1}{2}.\left(1-\frac{1}{9}\right)-\frac{1}{2}.\left(\frac{1}{2}-\frac{1}{10}\right)\)
=>\(S=\frac{1}{2}.\frac{8}{9}-\frac{1}{2}.\frac{2}{5}\)
=>\(S=\frac{4}{9}-\frac{1}{5}\)
=>\(S=\frac{11}{45}\)
Tính (theo mẫu)
Mẫu:\(\frac{5\cdot6\cdot7\cdot9}{12\cdot7\cdot27}\)=\(\frac{5\cdot6\cdot7\cdot9}{6\cdot2\cdot7\cdot9\cdot3}\)=\(\frac{5}{6}\)
a.\(\frac{3\cdot4\cdot7}{12\cdot8\cdot9}\)=.........................................................................
b.\(\frac{4\cdot5\cdot6}{12\cdot10\cdot8}\)=.......................................................................
c\(\frac{5\cdot6\cdot7}{12\cdot14\cdot15}\)=......................................................................
a.\(\frac{3\cdot4\cdot7}{12\cdot8\cdot9}\)= \(\frac{3\cdot4\cdot7}{3\cdot4\cdot8\cdot9}\)= \(\frac{7}{72}\)
b. \(\frac{4\cdot5\cdot6}{12\cdot10\cdot8}\)= \(\frac{4\cdot5\cdot2\cdot3}{3\cdot4\cdot5\cdot2\cdot8}\)= \(\frac{1}{8}\)
c.\(\frac{5\cdot6\cdot7}{12\cdot14\cdot15}\)= \(\frac{5\cdot6\cdot7}{2\cdot6\cdot2\cdot7\cdot3\cdot5}\)= \(\frac{1}{12}\)
Giúp mình với!
CHO \(a=\frac{2\cdot9\cdot8+3\cdot12\cdot10+4\cdot15\cdot12+...+98\cdot297\cdot200}{23\cdot4+3\cdot4\cdot5+4\cdot5\cdot6+...+98\cdot99\cdot100}\)
Tính a2
xin lỗi tại mình ko biết ghi dấu nhân làm sao