\(-1\frac{1}{12}:(\frac{1}{4}-\frac{1}{3})-1\frac{1}{15}:(\frac{1}{5}-\frac{1}{3})\)\()\)
Tính nhanh đc ko ạ
Thanks nhìu ạ :)))))
\(1\frac{1}{3}.1\frac{1}{8}.1\frac{1}{15}.1\frac{1}{24}.1\frac{1}{35}.1\frac{1}{48}.1\frac{1}{63}.1\frac{1}{80}\)
Tính nhanh giùm mik nhé! Gấp lắm ạ.Thanks mn nhìu
\(1\frac{1}{3}.1\frac{1}{8}.1\frac{1}{15}...1\frac{1}{80}\)
\(=\frac{4}{3}.\frac{9}{8}.\frac{16}{15}...\frac{81}{80}\)
\(=\frac{2.2}{1.3}.\frac{3.3}{2.4}.\frac{4.4}{3.5}...\frac{9.9}{8.10}\)
\(=\frac{2.3.4...9}{1.2.3...8}.\frac{2.3.4...9}{3.4.5...10}\)
\(=9.\frac{2}{10}\)
\(=9.\frac{1}{5}=\frac{9}{5}\)
1 và 1 phần 3 . 1 và 1 phần 8 . 1 và 1 phần 15 . 1 và 1 phần 24 . 1 và 1 phần 35 . 1 và 1 phần 48 . 1 và 1 phần 63 . 1 và 1 phần 80
= 4 phần 3 . 9 phần 8 . 16 phần 15 . 25 phần 24 . 36 phần 35 . 49 phần 48 . 64 phần 63 . 81 phần 80
= 3 phần 2 . 10 phần 9 . 15 phần 14 . 36 phần 35
= 5 phần 3 . 54 phần 49
= 90 phần 49
tính
\(B=\frac{1+2+2^2+2^3+...+2^{2008}}{1-2^{2009}}\)
\(B=\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+...+\frac{1}{9900}\)
bạn nào lm nhanh đc nhìu tick nè
1. Tính nhanh
a, \(\frac{7}{13}.\frac{7}{15}-\frac{5}{12}.\frac{21}{39}+\frac{49}{91}.\frac{8}{15}\)
b, \(\left(\frac{12}{199}+\frac{23}{200}-\frac{34}{201}\right).\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{6}\right)\)
c,\(\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
RÚT GỌN
\(A=\frac{12+\frac{12}{7}-\frac{12}{25}-\frac{12}{71}}{4+\frac{4}{7}-\frac{4}{25}-\frac{4}{71}}:\)\(\frac{3+\frac{3}{13}+\frac{3}{15}+\frac{3}{15}+\frac{3}{101}}{5+\frac{5}{13}+\frac{5}{15}+\frac{5}{101}}\)
\(B=\frac{\frac{1}{51}+\frac{1}{52}+\frac{1}{53}+......+\frac{1}{100}}{\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+.......+\frac{1}{99.100}}\)
1) a/ Tính:
\(1-\frac{1}{2};\frac{1}{2}-\frac{1}{3};\frac{1}{3}-\frac{1}{4};\frac{1}{4}-\frac{1}{5};\frac{1}{5}-\frac{1}{6}\)
Sử dụng kết quả của câu a/ để tính nhanh tổng sau :
\(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}\)
2)a/Tính nhanh:
B= \(\frac{1}{15}+\frac{1}{35}+\frac{1}{63}+\frac{1}{99}+\frac{1}{143}\)
b/ Tính nhanh:
C= \(\frac{1}{2}+\frac{1}{14}+\frac{1}{35}+\frac{1}{65}+\frac{1}{104}+\frac{1}{152}\)
BÀi 1: Thực hiện phép tính ( tính nhanh nếu có thể)
a.\(\left(-\frac{1}{2}\right)-\left(-\frac{3}{5}\right)+\left(-\frac{1}{9}\right)+\frac{1}{71}-\left(-\frac{2}{7}\right)+\frac{4}{35}-\frac{7}{18}\)
b.\(\left(3-\frac{1}{4}+\frac{2}{3}\right)-\left(5-\frac{1}{3}-\frac{6}{5}\right)-\left(6-\frac{7}{4}+\frac{3}{2}\right)\)
c.\(\frac{3}{5}:\left(\frac{-1}{15}-\frac{1}{6}\right)+\frac{3}{5}:\left(\frac{1}{3}-1\frac{1}{15}\right)\)
Tính nhanh:
\(A=\frac{1}{3}-\frac{3}{4}-\frac{-3}{5}+\frac{1}{72}-\frac{2}{9}-\frac{1}{36}+\frac{1}{15}\)
\(A=\frac{1}{3}-\frac{3}{4}-\frac{-3}{5}+\frac{1}{72}-\frac{2}{9}-\frac{1}{36}+\frac{1}{15}\)
\(\Rightarrow A=\frac{1}{3}+\frac{-3}{4}+\frac{3}{5}+\frac{1}{72}+\frac{-2}{9}+\frac{-1}{36}+\frac{1}{15}\)
\(\Rightarrow A=\left(\frac{1}{3}+\frac{3}{5}+\frac{1}{15}\right)+\left(\frac{-3}{4}+\frac{-2}{9}+\frac{-1}{36}\right)+\frac{1}{72}\)
\(\Rightarrow A=1+\left(-1\right)+\frac{1}{72}\)
\(\Rightarrow A=0+\frac{1}{72}\)
\(\Rightarrow A=\frac{1}{72}\)
Tính nhanh :
\(C=\frac{1}{3}+\frac{-3}{4}+\frac{3}{5}+\frac{1}{57}+\frac{-1}{36}+\frac{1}{15}+\frac{-2}{9}\)
\(D=\frac{1}{2}+\frac{-1}{5}+\frac{-5}{7}+\frac{1}{6}+\frac{-3}{35}+\frac{1}{3}+\frac{1}{41}\)
\(E=\frac{-1}{2}+\frac{3}{5}+\frac{-1}{9}+\frac{1}{127}+\frac{-7}{18}+\frac{4}{35}+\frac{2}{7}\)
C = 1/3 + -3/4 + 3/5 + 1/57 + -1/36 + 1/15 + -2/9
C = ( 1/3 + 1/57 ) + ( -3/4 + -1/36 ) + ( 3/5 + 1/15 ) + -2/9
C = ( 19/57 + 1/57 ) + ( -27/36 + -1/36 ) + ( 9/15 + 1/15 ) + -2/9
C = 20/57 + -28/36 + 10/15 + -2/9
C = 20/57 + -7/9 + 2/3 + -2/9
C = ( 20/57 + 2/3 ) + ( -7/9 + -2/9 )
C = 58/57 + -1
C = 1/57
D = 1/2 + -1/5 + -5/7 + 1/6 + -3/35 + 1/3 + 1/41
D = ( 1/2 + 1/3 + 1/6 ) + ( -1/5 + -5/7 +-3/35 ) + 1/41
D = ( 3/6 + 2/6 + 1/6 ) + ( -7/35 + -25/35 + -3/35 ) + 1/41
D = 1 + -1 + 1/41
D = 1/41
E = -1/2 + 3/5 + -1/9 + 1/127 + -7/18 + 4/35 + 2/7
E = ( -1/2 + -1/9 + -7/18 ) + ( 3/5 + 4/35 ) + 1/127 + 2/7
E = ( -9/18 + -2/18 + -7/18 ) + ( 21/35 + 4/35 ) + 1/127 + 2/7
E = -1 + 5/7 + 1/257 + 2/7
E = -1 + ( 5/7 + 2/7 ) + 1/127
E = -1 + 1 + 1/127
E = 1/127
\(C=\frac{1}{3}+\frac{-3}{4}+\frac{3}{5}+\frac{1}{57}+\frac{-1}{36}+\frac{1}{15}+\frac{-2}{9}.\)
\(C=\left(\frac{1}{3}+\frac{3}{5}+\frac{1}{15}\right)-\left(\frac{3}{4}+\frac{1}{36}+\frac{2}{9}\right)+\frac{1}{57}\)
\(C=1-1+\frac{1}{57}\)
\(C=\frac{1}{57}\)
D=1/2+-1/5+-5/7+1/6+-3/35+1/3+1/41
D=(1/2+1/6+1/3)-(1/5+3/35+5/7)+1/41
D=1-1+1/41
D=1/41
E=-1/2+3/5+-1/9+1/127+-7/18+4/35+2/7
E=(3/5+4/35+2/7)-(1/2+1/9+7/18)+1/127
E=1-1+1/127
E=1/127
Tính nhanh :
\(C=\frac{1}{3}+\frac{-3}{4}+\frac{3}{5}+\frac{1}{57}+\frac{-1}{36}+\frac{1}{15}+\frac{-2}{9}\)
\(C=\frac{1}{3}+\frac{-3}{4}+\frac{3}{5}+\frac{1}{57}+\frac{-1}{36}+\frac{1}{15}+\frac{-2}{9}\)
\(=\left(\frac{1}{3}+\frac{3}{5}+\frac{1}{15}\right)+\left(\frac{-3}{4}+\frac{-2}{9}+\frac{-1}{36}\right)+\frac{1}{57}\)
\(=\frac{5+9+1}{15}+\frac{\left(-27\right)+\left(-8\right)+\left(-1\right)}{36}+\frac{1}{57}\)
\(=\frac{15}{15}+\frac{-36}{36}+\frac{1}{57}=1-1+\frac{1}{57}=\frac{1}{57}\)