a) \(\frac{1}{2}\)\(\chi\)- \(\frac{3}{5}\)\(\chi\)= \(\frac{-7}{100}\)
b) \(^{x^2}\)\(\frac{7}{9}\)\(\chi\)= 0
c) /\(\frac{1}{2}\chi\)- \(\frac{1}{3}\)/ -1 = 0 , 25
d ) ( \(\chi\)+ \(\frac{4}{5}\)) \(^{^{ }3}\)= \(\frac{27}{125}\)
Rút gọn
B=\(4.\left(\frac{-1}{2}\right)^3:\left(\frac{4}{5}\right)^0.\frac{1}{2}-\frac{\frac{3}{5}-\frac{3}{9}+\frac{3}{13}}{\frac{7}{5}-\frac{7}{9}+\frac{7}{13}}\)
Giải chi tiết nha
\(B=4\cdot\left(-\frac{1}{2}\right)^3:\left(\frac{4}{5}\right)^0\cdot\frac{1}{2}-\frac{\frac{3}{5}-\frac{3}{9}+\frac{3}{13}}{\frac{7}{5}-\frac{7}{9}+\frac{7}{13}}\)
\(=4\cdot\frac{-1}{8}:1\cdot\frac{1}{2}-\frac{3\left(\frac{1}{5}-\frac{1}{9}+\frac{1}{13}\right)}{7\left(\frac{1}{5}-\frac{1}{9}+\frac{1}{13}\right)}\)
\(=-\frac{1}{4}-\frac{3}{7}=-\frac{19}{28}\)
Tính hợp lí:
A =\((\frac{2}{7}\times\frac{1}{4}-\frac{1}{3}\times\frac{2}{7})\div(\frac{2}{7}\times\frac{3}{9}-\frac{2}{7}\times\frac{2}{5})\)
B = \(\frac{(\frac{1}{5}-\frac{2}{7})\times\frac{3}{4}-\frac{3}{4}\times(\frac{1}{3}-\frac{2}{7})}{\frac{1}{5}\times\frac{2}{7}-\frac{1}{3}\times(\frac{2}{7}+\frac{3}{9})+\frac{3}{9}\times\frac{1}{5}}\)
CÓ LỜI GIẢI THÍCH CHI TIETS NHÉ AI NHANH MK TICK
A=\([\)\(\frac{2}{7}\)\(\times\)(\(\frac{1}{4}-\frac{1}{3}\))\(]\)\(\div\)\([\)(\(\frac{2}{7}\times\)(\(\frac{3}{9}-\frac{2}{5}\))\(]\)
=(\(\frac{2}{7}\times\)\(\frac{-1}{12}\))\(\div(\)\(\frac{2}{7}\times\)\(\frac{-1}{15}\))
=\(\frac{-1}{42}\)\(\div\)\(\frac{-2}{35}\)
=\(\frac{-1}{42}\)\(\times\)\(\frac{35}{-2}\)
=\(\frac{5}{12}\)
tính nhanh:
A=\(\frac{\frac{3}{7}-\frac{3}{17}+\frac{3}{37}}{\frac{5}{7}-\frac{5}{17}+\frac{5}{37}}+\frac{\frac{1}{2}-\frac{1}{3}+\frac{1}{4}-\frac{1}{5}}{\frac{7}{5}-\frac{7}{4}+\frac{7}{3}-\frac{7}{2}}\)
giải chi tiết nhé các bạn
A=\(\frac{\frac{3}{7}-\frac{3}{17}+\frac{3}{37}}{\frac{5}{7}-\frac{5}{17}+\frac{5}{37}}+\frac{\frac{1}{2}-\frac{1}{3}+\frac{1}{4}-\frac{1}{5}}{\frac{7}{5}-\frac{7}{4}+\frac{7}{3}-\frac{7}{2}}\)
\(=\frac{3\left(\frac{1}{7}-\frac{1}{17}+\frac{1}{37}\right)}{5\left(\frac{1}{7}-\frac{1}{17}+\frac{1}{37}\right)}+\frac{\frac{1}{2}-\frac{1}{3}+\frac{1}{4}-\frac{1}{5}}{-7\left(\frac{1}{2}-\frac{1}{3}+\frac{1}{4}-\frac{1}{5}\right)}\)
\(=\frac{3}{5}+\frac{1}{-7}=\frac{3}{5}-\frac{1}{7}\)
\(=\frac{21}{35}-\frac{5}{35}=\frac{16}{35}\)
Giúp mik 2 bài này với
A = \(\frac{1}{5}-\frac{3}{7}+\frac{5}{9}-\frac{2}{11}+\frac{7}{13}-\frac{9}{16}-\frac{7}{13}+\frac{2}{11}-\frac{5}{9}+\frac{3}{7}-\frac{1}{5}\)
B = \(\frac{1}{100}-\frac{1}{100.99}-\frac{1}{99.98}-\frac{1}{98.97}-...-\frac{1}{3.2}-\frac{1}{2.1}\)
Cố gắng giúp mik giải 1 cách chi tiết nhé
câu b nha
B= 1/100 - (1/2.1 + 1/3.2 + ... + 1/98.97 + 1/99.98 + 1/100.99)
B=1/100 - (1 - 1/2 + 1/2 - 1/3 + 1/3 - ... - 1/99 + 1/99 - 1/100)
B=1/100-(1-1/100)
B=1/100-99/100
B= - 98/100
B= - 49/50
đ ú g nha
- Câu a ~> http://olm.vn/hoi-dap/question/183158.html
\(\sqrt[4]{3}.243^{\frac{2\chi+3}{\chi+8}=\frac{1}{9}.9^{\frac{\chi+8}{\chi+2}}}\)
Giải chi tiết giúp mk bài này với: Tính hợp lý :
\(A=\left(-\frac{2}{9}\right)-\left(-\frac{1}{121}\right)+\left(-\frac{3}{5}\right)+\left(-\frac{1}{2}\right)-\left(-1\frac{13}{18}\right)-\frac{1}{7}-\frac{9}{35}\)
\(B=0,75+\frac{3}{5}+\left(\frac{2}{9}-1\frac{3}{5}+1\frac{1}{4}\right)\)
\(C=1-2+3-4+...+79-80\)
c) C = ( 1 - 2 ) + ( 3 - 4 ) + ... + ( 79 - 80 )
C = ( -1 ) + ( -1 ) + ... + ( -1 )
C = ( -1 ) x ( 80 - 1 + 1 ) : 2
C = ( -1 ) x 80 : 2
C = ( -40 )
C=1-2+3-4+...+79-80
=(1-2)+(3-4)+...+(79-80)
=-1+(-1)+...+(-1) (có 80 số hạng bàng -1)
=-1*80
=-80
hepl me
Tính:\(\frac{\frac{3}{7}-\frac{3}{11}+\frac{3}{13}}{\frac{5}{7}-\frac{5}{11}+\frac{5}{13}}+\frac{\frac{1}{2}-\frac{1}{3}+\frac{1}{4}}{\frac{5}{4}+\frac{5}{8}-\frac{5}{6}}\)
Giải chi tiết nha
ta có \(\frac{\frac{3}{7}-\frac{3}{11}+\frac{3}{13}}{\frac{5}{7}-\frac{5}{11}+\frac{5}{13}}=\frac{3\left(\frac{1}{7}-\frac{1}{11}+\frac{1}{13}\right)}{5\left(\frac{1}{7}-\frac{1}{11}+\frac{1}{13}\right)}=\frac{3}{5}\)
và \(\frac{\frac{1}{2}-\frac{1}{3}+\frac{1}{4}}{\frac{5}{4}+\frac{5}{8}-\frac{5}{6}}=\frac{2\left(\frac{1}{2.2}-\frac{1}{3.2}+\frac{1}{4.2}\right)}{5\left(\frac{1}{4}+\frac{1}{8}-\frac{1}{6}\right)}=\frac{2\left(\frac{1}{4}+\frac{1}{8}-\frac{1}{6}\right)}{5\left(\frac{1}{4}+\frac{1}{8}-\frac{1}{6}\right)}=\frac{2}{5}\)
Vậy \(\frac{\frac{3}{7}-\frac{3}{11}+\frac{3}{13}}{\frac{5}{7}-\frac{5}{11}+\frac{5}{13}}+\frac{\frac{1}{2}-\frac{1}{3}+\frac{1}{4}}{\frac{5}{4}+\frac{5}{8}-\frac{5}{6}}=\frac{3}{5}+\frac{2}{5}=\frac{5}{5}=1\)
ĐS: 1
Tính
A) \(\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-1\frac{15}{17}+\frac{2}{3}\)
B) \(\left(-2\right)^3\times\left(\frac{3}{4}-0,25\right):\left(2\frac{1}{4}-1\frac{1}{6}\right)\)
Tìm x
A) \(4\frac{1}{3}:\frac{\chi}{4}=6:0,3\)
B) \(\left(2^3:4\right)\times2^{\left(\chi+1\right)}=64\)
Tính:
b) \(\left(-2\right)^3.\left(\frac{3}{4}-0,25\right):\left(2\frac{1}{4}-1\frac{1}{6}\right)\)
\(=\left(-2\right)^3.\left(\frac{3}{4}-\frac{1}{4}\right):\left(\frac{9}{4}-\frac{7}{6}\right)\)
\(=\left(-8\right).\frac{1}{2}:\frac{13}{12}\)
\(=\left(-4\right):\frac{13}{12}\)
\(=-\frac{48}{13}.\)
Tìm x
a) \(4\frac{1}{3}:\frac{x}{4}=6:0,3\)
⇒ \(\frac{13}{3}:\frac{x}{4}=20\)
⇒ \(\frac{x}{4}=\frac{13}{3}:20\)
⇒ \(\frac{x}{4}=\frac{13}{60}\)
⇒ \(x.60=4.13\)
⇒ \(x.60=52\)
⇒ \(x=52:60\)
⇒ \(x=\frac{13}{15}\)
Vậy \(x=\frac{13}{15}.\)
b) \(\left(2^3:4\right).2^{x+1}=64\)
⇒ \(\left(8:4\right).2^{x+1}=64\)
⇒ \(2.2^{x+1}=64\)
⇒ \(2^{x+1}=64:2\)
⇒ \(2^{x+1}=32\)
⇒ \(2^{x+1}=2^5\)
⇒ \(x+1=5\)
⇒ \(x=5-1\)
⇒ \(x=4\)
Vậy \(x=4.\)
Chúc bạn học tốt!
Tim x;biet:\(\frac{\chi-2}{\chi-1}=\frac{\chi+4}{\chi+7}\)
\(\frac{x-2}{x-1}=\frac{x+4}{x+7}=\frac{x-2-x-4}{x-1-x-7}=\frac{-6}{-8}=\frac{3}{4}\)
\(\Rightarrow4\left(x-2\right)=3\left(x-1\right)\Rightarrow4x-8=3x-3\Rightarrow x=5\)