rút gọn phân số \(\frac{10+5}{4\cdot5}\)
Rút gọn phân số
\(\frac{3^4\cdot5-3^6}{3^4\cdot13+3^4}\)
\(\frac{3^4\cdot5-3^6}{3^4\cdot13+3^4}\)
\(=\frac{3^4\cdot\left(5-3^2\right)}{3^4\cdot\left(13+1\right)}\)
\(=\frac{5-9}{13+1}\)
\(=-\frac{4}{14}=-\frac{2}{7}\)
\(\frac{3^4.5-3^6}{3^4.13+3^4}=\frac{3^4.5-3^4.9}{3^4\left(13+1\right)}=\frac{3^4\left(5-9\right)}{3^4.14}=\frac{3^4.\left(-4\right)}{3^4.14}=\frac{-4}{14}=\frac{-2}{7}\)
a, Rút gọn phân số :
\(\frac{\left(-2\right)^3\cdot3^3\cdot5^3\cdot7\cdot8}{3\cdot5^3\cdot2^4\cdot42}\)
b, so sánh không qua quy đồng :
A=\(\frac{-7}{10^{2005}}\)+\(\frac{-15}{10^{2006}}\)
B=\(\frac{-15}{10^{2005}}\)+\(\frac{-7}{10^{2006}}\)
két bn vớ mk . mk bày cho chớ làm vào đây tốn thời gian lắm
\(A=\frac{\left(-2\right)^3\cdot3^3\cdot5^3\cdot7\cdot8}{3\cdot5^3\cdot2^4\cdot42}\)
\(=\frac{\left(-2\right)^3\cdot3^3\cdot6^3\cdot5^3\cdot7\cdot2^3}{3\cdot5^3\cdot2^4\cdot2\cdot3\cdot7}\)
\(=\frac{\left(-2\right)^3\cdot3^8\cdot5^3\cdot2^3\cdot7}{3^2\cdot5^3\cdot2^5\cdot7}=-2\cdot3^6\)
câu b để nghĩ...
Rút gọn phân số sau : \(\frac{2^3\cdot3^3\cdot5^3\cdot7\cdot8}{3\cdot2^4\cdot5^3\cdot14}\)
Ai xong trước và đúng mình tích cho
\(=\frac{2^3.3^3.5^3.2^3.7}{3.2^4.5^3.2.7}=\frac{2^6.5^3.3^3}{3.2^5.5^3}=2.3^2=2.9=18\)
=\(\frac{2^3\cdot3^3\cdot5^3\cdot2^3\cdot7}{3\cdot2^4\cdot5^3\cdot2\cdot7}=\frac{2^{3_{ }}\cdot3^3\cdot2^3}{3\cdot2^4\cdot2}=\frac{1728}{96}=\frac{18}{1}=18\)
2 câu trên câu nào cũng đúng. nhưng làm theo cách 2 thì nhanh hơn
Rút gọn phân số:
a,\(\frac{21\cdot75\cdot130\cdot169}{39\cdot60\cdot11\cdot198}\)
b,\(\frac{2^4\cdot5^2:11^2\cdot7}{2^3\cdot5^3\cdot7^2.11}\)
a) \(\frac{21.75.130.169}{39.60.11.198}=\frac{34602750}{5096520}=\frac{29575}{4536}\)
b) \(\frac{2^4.5^2:11^2.7}{2^3.5^3.7^2.11}\Leftrightarrow\frac{2^3.2^1.5^2:11.11.7}{2^3.5^2.5^1.7.7.11}=\frac{2^1.11.7}{5^1.7.11}=\frac{154}{385}\)
Vậy : .. . . . . . . . . . .
Rút gọn
\(\frac{10+5}{4\cdot5}\)\(\frac{2^2\cdot9}{27\cdot2}\)1.\(\frac{10+5}{4.5}=\frac{2.5+1.5}{4.5}=\frac{\left(2+1\right).5}{4.5}=\frac{3.5}{4.5}=\frac{3}{4}\)
2. \(\frac{2^2.9}{27.2}=\frac{2.2.3.3}{3.3.3.2}=\frac{2}{3}\)
Rút gọn :\(\frac{2\cdot3\cdot5+4\cdot9\cdot25+6\cdot9\cdot35+10\cdot21\cdot40}{2\cdot3\cdot5+4\cdot9\cdot35+6\cdot9\cdot49+10\cdot21\cdot56}\)
Bài 1: Rút gọn rồi quy đồng
\(\frac{4\cdot5+4\cdot11}{8\cdot7-4\cdot3}\) \(\frac{-15\cdot8+10\cdot7}{5\cdot6+20\cdot3}\)và \(\frac{2^4\cdot5^2\cdot7}{2^3\cdot5\cdot7^3\cdot11}\)
\(\frac{16}{11},-\frac{5}{9},\frac{10}{539}\)
Rút gọn biểu thức:
\(\frac{2^{12}\cdot13+2^{12}\cdot65}{2^{10}\cdot104}+\frac{3^{10}\cdot11+3^{10}\cdot5}{3^9\cdot2^4}\)
\(\frac{2^{12}.13+2^{12}.65}{2^{10}.104}+\frac{3^{10}.11+3^{10}.5}{3^9.2^4}\)
\(\Rightarrow\frac{2^{12}.\left(13+65\right)}{2^{10}.104}+\frac{3^{10}.\left(11+5\right)}{3^9.2^4}\)
\(\Rightarrow\frac{2^{12}.78}{2^{10}.104}+\frac{3^{10}.2^4}{3^9.2^4}\)
\(=\frac{2^2.3}{4}+3\)
\(=3+3=6\)
sắp xếp lại các phân số sau theo thứ tự lớn dần từ tái sang phải :2/5,1/-4,4/9,-3/4
rút gọn \(\frac{2\cdot5\cdot13}{26\cdot35}\)\(\frac{24\cdot5-24}{4-28}\)\(\frac{123\cdot6+123\cdot4}{3-126}\)
ai làm đúng mình sẽ tick
1). Sx:-3/4 ; 1/-4 ; 2/5 ; 4/9
2). \(\frac{2.5.13}{26.35}+\frac{24.5-24}{4-28}+\frac{123.6+123.4}{3-126}=\frac{2.5.13}{2.13.5.7}+\frac{24.\left(5-1\right)}{4.\left(1-7\right)}+\frac{123.\left(6+4\right)}{-123}=\frac{1}{7}+4-10=\frac{1}{7}+\frac{42}{7}=\frac{43}{7}\)