Tính nhanh
\(A=5\frac{3}{7}+\left(-5,35\right)+\frac{1}{3}+\left(-2,41\right)+\frac{3}{21}+\left(-1,24\right)\)
Tính hợp lý :
\(5\frac{3}{7}+\left(-5,35\right)+\frac{1}{3}+\left(-2,41\right)+\frac{3}{21}+\left(-1,24\right)\)
Tính A=\(5\frac{3}{7}+\left(-5,35\right)+\frac{1}{3}+\left(-2,41\right)+3,21+\left(-1,24\right)\)
Tính:
A = $5\frac{3}{7}+\left(-5,35\right)+\frac{1}{3}+\left(-2,41\right)+\frac{3}{21}+\left(-1,24\right)$537 +(−5,35)+13 +(−2,41)+321 +(−1,24)
B = $4\frac{25}{16}+25.\left(\frac{9}{16}-\frac{117}{64}\right):\frac{27}{8}$42516 +25.(916 −11764 ):278
Trình bày cách giải và đáp án giúp mình nha! ^^
Tính:
A = \(5\frac{3}{7}+\left(-5,35\right)+\frac{1}{3}+\left(-2,41\right)+\frac{3}{21}+\left(-1,24\right)\)
B = \(4\frac{25}{16}+25.\left(\frac{9}{16}-\frac{117}{64}\right):\frac{27}{8}\)
Mấy dấu gạch không phải là trị tuyệt đối đâu mà khi mình ghi thì nó có sẵn
Trình bày cách giải và đáp án giúp mình nha! ^^
thực hiện phép tính : ( tính nhanh nếu có thể )
a) \(\left(\frac{11}{12}:\frac{33}{16}\right).\frac{3}{5}+\frac{7}{23}.\left[\left(\frac{-8}{6}+\frac{-45}{18}\right)\right]\)
b) \(\left(\frac{-2}{3}+\frac{3}{7}\right):\frac{4}{5}+\left(\frac{-1}{3}+\frac{4}{7}\right):\frac{4}{5}\)
c) \(\frac{5}{9}:\left(\frac{1}{11}-\frac{5}{22}\right)+\frac{5}{9}:\left(\frac{1}{15}-\frac{2}{3}\right)\)
d) \(\frac{-3}{4}.\frac{12}{-5}.\frac{-25}{6}+\left(-2\right).\frac{-38}{21}.\frac{-7}{4}.\frac{-3}{8}\)
thực hiện phép tính (tính nhanh nếu có thể) :
a)\(1\frac{3}{19}+\frac{8}{21}-\frac{3}{19}+0.5+\frac{13}{21}\)
b)\(\left(-\frac{3}{4}+\frac{2}{7}\right):\frac{3}{7}+\left(\frac{5}{7}+\frac{-1}{4}\right):\frac{3}{7}\)
c)\(\left(\frac{1}{6}\right)^7\times6\)
d)\(\left(\frac{-1}{2}\right)^3+\frac{1}{2}:3\)
a) \(1\frac{3}{19}+\frac{8}{21}-\frac{3}{19}+0.5+\frac{13}{21}\)
\(=\left(1\frac{3}{19}-\frac{3}{19}\right)+\left(\frac{8}{21}+\frac{13}{21}\right)+0.5\)
\(=1+1+0.5=2.5\)
b) \(\left(-\frac{3}{4}+\frac{2}{7}\right):\frac{3}{7}+\left(\frac{5}{7}+\frac{-1}{4}\right):\frac{3}{7}\)
\(=\left(\frac{-3}{4}+\frac{2}{7}+\frac{5}{7}+\frac{-1}{4}\right):\frac{3}{7}\)
\(=0:\frac{3}{7}=0\)
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.\(\frac{3}{5}:\left(\frac{-1}{15}-\frac{1}{6}\right)+\frac{3}{5}:\left(\frac{1}{3}-1\frac{1}{15}\right)\)
Bài 1 Thưc hiện phép tính ( tính nhanh nếu có thể)
a)\(\frac{-1}{24}-\left[\frac{1}{4}-\left(\frac{1}{2}-\frac{7}{8}\right)\right]\)
b)\(\left(\frac{5}{7}-\frac{7}{5}\right)-\left[\frac{1}{2}-\left(\frac{-2}{7}-\frac{1}{10}\right)\right]\)
C)\(\left(\frac{-1}{2}\right)-\left(\frac{-3}{5}\right)+\left(\frac{-1}{9}\right)+\frac{1}{17}-\left(\frac{-2}{7}\right)+\frac{4}{35}-\frac{7}{18}\)
d)\(\left(3-\frac{1}{4}+\frac{2}{3}\right)-\left(5-\frac{1}{3}-\frac{6}{5}\right)-\left(6-\frac{7}{4}+\frac{3}{2}\right)\)
tính nhanh biểu thức sau:
A=\(\frac{1}{\left(x+1\right)\left(x+3\right)}+\frac{1}{\left(x+3\right)\left(x+5\right)}+\frac{1}{\left(x+5\right)\left(x+7\right)}+\frac{1}{\left(x+7\right)\left(x+9\right)}+\frac{1}{\left(x+9\right)\left(x+11\right)}\)
Ta có: \(A=\frac{1}{\left(x+1\right)\left(x+3\right)}+\frac{1}{\left(x+3\right)\left(x+5\right)}+.....+\frac{1}{\left(x+9\right)\left(x+11\right)}\)
\(\Rightarrow A=\frac{1}{x+1}-\frac{1}{x+3}+\frac{1}{x+3}-\frac{1}{x+5}+....+\frac{1}{x+9}-\frac{1}{x+11}\)
\(\Rightarrow A=\frac{1}{x+1}-\frac{1}{x+11}\)
\(\Rightarrow A=\frac{x+11-x+1}{\left(x+1\right)\left(x+11\right)}=\frac{12}{\left(x+1\right)\left(x+11\right)}\)