Tính:
E=\(\frac{\frac{6}{7}-\frac{6}{9}+\frac{6}{11}-\frac{6}{13}}{\frac{8}{7}+\frac{8}{11}-\frac{8}{9}-\frac{8}{13}}\)
\(\frac{\frac{6}{7}-\frac{6}{9}+\frac{6}{11}-\frac{6}{13}}{\frac{8}{7}-\frac{8}{9}+\frac{8}{11}-\frac{8}{13}}\)
đặt 6 ở tử làm thừa số chung và 8 ở mẫu làm thừa số chung.rút gọn ta được kq là 6/8=3/4
\(\frac{\frac{6}{7}-\frac{6}{9}+\frac{6}{11}-\frac{6}{13}}{\frac{8}{7}-\frac{8}{9}+\frac{8}{11}-\frac{8}{13}}\)Tính nha các bạn
\(\frac{\frac{6}{7}-\frac{6}{9}+\frac{6}{11}-\frac{6}{13}}{\frac{8}{7}-\frac{8}{9}+\frac{8}{11}-\frac{8}{13}}\)
=\(\frac{6.\left(\frac{1}{7}-\frac{1}{9}+\frac{1}{11}-\frac{1}{13}\right)}{8.\left(\frac{1}{7}-\frac{1}{9}+\frac{1}{11}-\frac{1}{13}\right)}\)
=\(\frac{6}{8}\)
=\(\frac{3}{4}\)
có z ko tính đk s p hỏi
tính tử òi tính mẫu òi tính cả thế nhé
\(\frac{\frac{6}{7}-\frac{6}{9}+\frac{6}{11}-\frac{6}{13}}{\frac{8}{7}-\frac{8}{9}+\frac{8}{11}-\frac{8}{13}}\)
Tính
P= \(\frac{\frac{6}{8}-\frac{6}{10}+\frac{6}{14}+\frac{6}{26}}{\frac{11}{4}+\frac{11}{5}+\frac{11}{7}+\frac{11}{13}}\)
Q=\(\frac{\frac{9}{1}+\frac{8}{2}+.....+\frac{1}{9}}{\frac{1}{2}+\frac{1}{3}+....+\frac{1}{10}}\)
Ta có :
\(P=\frac{\frac{6}{8}+\frac{6}{10}+\frac{6}{14}+\frac{6}{26}}{\frac{11}{4}+\frac{11}{5}+\frac{11}{7}+\frac{11}{13}}\)
\(\Rightarrow P=\frac{\frac{3}{4}+\frac{3}{5}+\frac{3}{7}+\frac{3}{13}}{11\left(\frac{1}{4}+\frac{1}{5}+\frac{1}{7}+\frac{1}{13}\right)}\)
\(\Rightarrow P=\frac{3\left(\frac{1}{4}+\frac{1}{5}+\frac{1}{7}+\frac{1}{13}\right)}{11\left(\frac{1}{4}+\frac{1}{5}+\frac{1}{7}+\frac{1}{13}\right)}\)
\(\Rightarrow P=\frac{3}{11}\)
Vậy \(P=\frac{3}{11}\)
\(P=\frac{\frac{3}{4}-\frac{3}{5}+\frac{3}{7}+\frac{3}{13}}{\frac{11}{4}-\frac{11}{5}+\frac{11}{7}+\frac{11}{13}}=\frac{3}{11}\)
đề bài của bn sai nên mk sửa luôn nha
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)\(\frac{11}{8}-\frac{5}{8}:\frac{3}{4}=\frac{11}{8}-\frac{5}{8}x\frac{4}{3}=\frac{11}{8}-\frac{10}{24}=\frac{23}{24}\) ......
Mai Hồng Ngọc? Vũ Thị Thu Hằng? Ai đúng dzậy -_-*
Bài 1: Tính (hợp lý nếu có thể)
a) \(\frac{8}{40}+\frac{-4}{20}-\frac{3}{5}\)
b) \(\frac{-7}{12}+\frac{-2}{12}-\frac{-3}{36}\)
c) \((\frac{1}{6}+\frac{-4}{13})-(\frac{-17}{6}-\frac{30}{13})\)
d) \(-\frac{-5}{4}+\frac{7}{4}-\frac{-11}{7}+\frac{2}{7}\)
e) \(-\frac{1}{8}+\frac{-7}{9}+\frac{-7}{8}+\frac{6}{7}+\frac{2}{14}\)
f) \(\frac{-2}{9}-\frac{11}{-9}+\frac{5}{7}-\frac{-6}{-7}\)
Bài 1:
a) Ta có: \(\frac{8}{40}+\frac{-4}{20}-\frac{3}{5}\)
\(=\frac{1}{5}+\frac{-1}{5}-\frac{3}{5}\)
\(=\frac{-3}{5}\)
b) Ta có: \(\frac{-7}{12}+\frac{-2}{12}-\frac{-3}{36}\)
\(=\frac{-7}{12}+\frac{-2}{12}-\frac{-1}{12}\)
\(=\frac{-9+1}{12}=\frac{-8}{12}=\frac{-2}{3}\)
c) Ta có: \(\left(\frac{1}{6}+\frac{-4}{13}\right)-\left(-\frac{17}{6}-\frac{30}{13}\right)\)
\(=\frac{1}{6}+\frac{-4}{13}+\frac{17}{6}+\frac{30}{13}\)
\(=3+2=5\)
d) Ta có: \(-\frac{-5}{4}+\frac{7}{4}-\frac{-11}{7}+\frac{2}{7}\)
\(=\frac{5}{4}+\frac{7}{4}+\frac{11}{7}+\frac{2}{7}\)
\(=3+\frac{13}{7}=\frac{21}{7}+\frac{13}{7}=\frac{34}{7}\)
e) Ta có: \(-\frac{1}{8}+\frac{-7}{9}+\frac{-7}{8}+\frac{6}{7}+\frac{2}{14}\)
\(=-1+1+\frac{-7}{9}\)
\(=-\frac{7}{9}\)
f) Ta có: \(\frac{-2}{9}-\frac{11}{-9}+\frac{5}{7}-\frac{-6}{-7}\)
\(=\frac{-2-\left(-11\right)}{9}+\frac{5-6}{7}\)
\(=1+\frac{-1}{7}=\frac{7}{7}+\frac{-1}{7}=\frac{6}{7}\)
1 TÍNH :
a, \(\frac{1}{6}.\frac{9}{-8}.\left(\frac{-12}{11}\right)\)
b, \(\frac{1}{8}.\frac{-3}{7}+\frac{1}{8}.\frac{-4}{7}\)
c, \(\frac{7}{13}.\frac{3}{-5} +\frac{6}{13}.\frac{-3}{5}\)
Tính :
a) \(\frac{1}{6}.\frac{9}{-8}.\left(-\frac{12}{11}\right)=\frac{1.9.\left(-12\right)}{6.\left(-8\right).11}=\frac{1.3.3}{2.2.11}=\frac{9}{44}\)
b) \(\frac{1}{8}.\frac{-3}{7}+\frac{1}{8}.\frac{-4}{7}\)
\(=\frac{1}{8}.\left(-\frac{3}{7}+\frac{-4}{7}\right)\)
\(=\frac{1}{8}.\frac{-7}{7}=\frac{1}{8}.\left(-1\right)\)
\(=-\frac{1}{8}\)
c) \(\frac{7}{13}.\frac{3}{-5}+\frac{6}{13}.\frac{-3}{5}\)
\(=-\frac{3}{5}.\left(\frac{7}{13}+\frac{6}{13}\right)\)
\(=-\frac{3}{5}.\frac{13}{13}=-\frac{3}{5}.1\)
\(=-\frac{3}{5}\)
a, \(\frac{1}{6}.\frac{9}{-8}.\frac{-12}{11}\)
\(\Rightarrow\frac{9}{8}.\frac{2}{11}\)
\(\Rightarrow\frac{9}{4}.\frac{1}{11}\)
\(\Rightarrow\frac{9}{44}\)
b,\(\frac{1}{8}.\frac{-3}{7}+\frac{1}{8}.\frac{-4}{7}\)
\(\Rightarrow\frac{-3}{56}-\frac{1}{2}.\frac{1}{7}\)
\(\Rightarrow\frac{-3}{56}-\frac{1}{2}.\frac{1}{7}\)
\(\Rightarrow\frac{-3}{56}-\frac{1}{14}\)
\(\Rightarrow\frac{-1}{8}\)
c,\(\frac{7}{13}.\frac{3}{-5}+\frac{6}{13}.\frac{-3}{5}\)
\(\Rightarrow\frac{-21}{65}-\frac{18}{65}\)
\(\Rightarrow\frac{-3}{5}\)
a, \(\frac{1}{6}.\frac{9}{-8}.\frac{-12}{11}\)
\(=\frac{1}{6}.\frac{-9}{8}.\frac{-12}{11}\)
\(=\frac{-3}{16}.\frac{-12}{11}\)
\(=\frac{9}{44}\)
b, \(\frac{1}{8}.\frac{-3}{7}+\frac{1}{8}.\frac{-4}{7}\)
\(=\frac{1}{8}.\left(\frac{-3}{7}+\frac{-4}{7}\right)\)
\(=\frac{1}{8}.\left(-1\right)\)
\(=\frac{-1}{8}\)
c, \(\frac{7}{13}.\frac{3}{-5}+\frac{6}{13}.\frac{-3}{5}\)
\(=\frac{7}{13}.\frac{-3}{5}+\frac{6}{13}.\frac{-3}{5}\)
\(=\frac{-3}{5}.\left(\frac{7}{13}+\frac{6}{13}\right)\)
\(=\frac{-3}{5}.1\)
\(=\frac{-3}{5}\)
bài 1 : tính phân số:
a) \(\frac{5}{7}+\frac{4}{9}=?;\frac{4}{5}-\frac{2}{3}=?;\frac{9}{11}+\frac{3}{8}=?;\frac{16}{25}-\frac{2}{5}=?\)=?
b)\(5+\frac{3}{5}=?;10-\frac{9}{16}=?;\frac{2}{3}-\left(\frac{1}{6}+\frac{1}{8}\right)=?\)
c)\(\frac{5}{7}+\frac{7}{6}=?;\frac{7}{12}+\frac{17}{18}=?;\frac{9}{8}+\frac{15}{32}=?;4+\frac{35}{45}=?\)
d)\(\frac{11}{4}-\frac{15}{16}=?;\frac{5}{6}-\frac{5}{8}=?;\frac{196}{64}-2=?;3-\frac{13}{9}=?\)
e)\(\frac{8}{5}+\frac{7}{6}+\frac{5}{9}-2=?;3-\frac{5}{6}-\frac{4}{9}+\frac{32}{24}=?\)
a)\(\dfrac{5}{7}+\dfrac{4}{9}=\dfrac{45}{63}+\dfrac{28}{63}=\dfrac{73}{63}\) ; \(\dfrac{9}{11}+\dfrac{3}{8}=\dfrac{72}{88}+\dfrac{33}{88}=\dfrac{105}{88}\)
\(\dfrac{4}{5}-\dfrac{2}{3}=\dfrac{12}{15}-\dfrac{10}{15}=\dfrac{2}{15}\); \(\dfrac{16}{25}-\dfrac{2}{5}=\dfrac{16}{25}-\dfrac{10}{25}=\dfrac{6}{25}\)
BÀI ÔN SỐ HỌC
1. Thực hiện mỗi phép tính sau bằng 2 cách:
a)\(3\frac{4}{9}+5\frac{1}{6}\)
Ví dụ :
Cách 1: \(3\frac{4}{9}+5\frac{1}{6}=\frac{31}{9}+\frac{31}{6}=\frac{62}{18}+\frac{93}{18}=\frac{155}{18}=8\frac{11}{18}\)
Cách 2:\(3\frac{4}{9}+5\frac{1}{6}=3\frac{8}{18}+5\frac{3}{18}=8\frac{11}{18}\)
b)\(8\frac{1}{14}-6\frac{3}{7}\)
c)\(7-3\frac{6}{7}\)
2. Áp dụng tính chất phép tính & qui tắc dấu ngoặc để tính giá trị các biểu thức sau:
a)A =\(11\frac{3}{13}-\left(3\frac{4}{7}+6\frac{3}{13}\right)\)
b)B =\(\left(7\frac{4}{9}+3\frac{8}{13}\right)-5\frac{4}{3}\)
c)C =\(\frac{-2}{7}.\frac{5}{11}+\frac{-2}{7}.\frac{6}{11}+5\frac{4}{7}\)
d)D =\(0,7.1\frac{3}{5}.30.0,375.\frac{4}{7}\)
3.Tìm các số nghịch đảo của các số sau : \(\frac{4}{7};6\frac{3}{8};\frac{-3}{17};0.37\)
4.Tìm x, biết :
0,5-\(\frac{2}{3}x=\frac{5}{12}\)