\(\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-\frac{20}{15}+\frac{1}{6}\)
Thực hiện phép tính bằng cách hợp lí
a, \(\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-1\frac{15}{17}+\frac{2}{3}\) b, \(\left(-2\right)^3.\left(\frac{3}{4}-0,25\right):\left(2\frac{1}{4}-1\frac{1}{6}\right)\)
Bài 1: Thực hiện phép tính a) \(\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-1\frac{7}{21}+2\)
Bài 1 :
\(a,\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-1\frac{7}{21}+2\)
\(=\left(\frac{15}{34}+\frac{19}{34}\right)+\left(\frac{7}{21}-1\frac{7}{21}\right)+2\)
\(=1-1+2\)
\(=2\)
Học tốt
Bài 1 :
a, 15/34+7/21+19/34-1 7/21+2
= 15/34+1/3+19/34-4/3+2
= (15/34+19/34)+(1/3-4/3)+2
= 1+(-1)+2=0+2=2
TÍNH :
\(A=\frac{\frac{5}{18}+\frac{6}{19}+\frac{7}{20}+\frac{8}{21}+....+\frac{21}{34}-17}{\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+....+\frac{1}{33.34}}\)
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!
a,\(\frac{15}{34}\)+\(\frac{7}{21}\)+\(\frac{19}{34}\)-\(\frac{36}{21}\)+\(\frac{2}{3}\)
Ta có: \(\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-\frac{36}{21}+\frac{2}{3}\)
\(=\frac{15}{34}+\frac{19}{34}+\frac{7}{21}-\frac{36}{21}+\frac{2}{3}\)
\(=1-\frac{29}{31}+\frac{2}{3}=\frac{2}{31}+\frac{2}{3}=\frac{68}{93}\)
\(\frac{35}{34}\)+ \(\frac{7}{21}\)+ \(\frac{19}{54}\)+\(\frac{20}{15}\)+\(\frac{2016}{2017}\)
tính giá trị biểu thức
\(A=\frac{-378.132+189.64}{15+18+21+......+45+48}\)
\(B=1,4.\frac{15}{14}-\left(\frac{4}{5}+\frac{2}{5}\right):2\frac{1}{5}-\frac{\frac{73}{77}+\frac{73}{165}+\frac{73}{285}}{\frac{25}{24}+\frac{15}{180}+\frac{20}{285}}\)
\(C=\frac{7+\frac{7}{12}-\frac{7}{144}+\frac{7}{60}}{5+\frac{6}{12}-\frac{5}{144}}.\frac{\frac{3}{4}-\frac{3}{16}+\frac{3}{64}-\frac{3}{256}}{1-\frac{1}{4}+\frac{1}{16}-\frac{1}{34}}-\frac{1}{20}\)
A =\(\frac{15}{34}+\frac{7}{21}+\frac{9}{34}-1\frac{15}{17}+\frac{2}{3}\)
B = \(16\frac{2}{7}:\left(-\frac{3}{5}\right)-28\frac{2}{7}:\left(-\frac{3}{5}\right)\)
\(A=\frac{15}{34}+\frac{7}{21}+\frac{9}{34}-1\frac{15}{17}+\frac{2}{3}\)
\(=\frac{12}{17}+\frac{1}{3}-\frac{32}{17}+\frac{2}{3}\)
\(=-\frac{20}{17}+\frac{1}{3}+\frac{2}{3}\)
\(=-\frac{20}{17}+1\)
\(=-\frac{3}{17}\)
\(B=16\frac{2}{7}:\left(-\frac{3}{5}\right)-28\frac{2}{7}:\left(-\frac{3}{5}\right)\)
\(=\left(\frac{114}{7}-\frac{198}{7}\right):\left(-\frac{3}{5}\right)\)
\(=\left(-12\right):\left(-\frac{3}{5}\right)\)
\(=20\)
A\(=\frac{15}{34}+\frac{7}{21}+\frac{9}{34}-1\frac{15}{17}+\frac{2}{3}\)
\(=\left(\frac{15}{34}+\frac{9}{34}\right)+\left(\frac{7}{21}+\frac{2}{3}\right)-1\frac{15}{17}\)
\(=\left(\frac{14}{17}-\frac{15}{17}\right)+1-1\)
\(=-\frac{1}{17}\)
\(B=16\frac{2}{7}:\left(-\frac{3}{5}\right)-28\frac{2}{7}:\left(-\frac{3}{5}\right)\)
\(B=-\frac{3}{5}.\left(16\frac{2}{7}-28\frac{2}{7}\right)\)
\(B=-\frac{3}{5}.\left(-12\right)\)
\(B=\frac{36}{5}\)
Hoctot
A=\(\frac{15}{34}\)+ \(\frac{7}{21}\)+ \(\frac{9}{34}\)- 1\(\frac{15}{17}\)+ \(\frac{2}{3}\)
= ( \(\frac{15}{34}\)+ \(\frac{9}{34}\)) + ( \(\frac{7}{21}\)+ \(\frac{2}{3}\)) - \(\frac{32}{17}\)
= \(\frac{24}{34}\)+ ( \(\frac{7}{21}\)+ \(\frac{14}{21}\)) - \(\frac{32}{17}\)
=\(\frac{12}{17}\)+ \(\frac{21}{21}\)- \(\frac{32}{17}\)
= ( \(\frac{12}{17}\) - \(\frac{32}{17}\)) +1
=\(\frac{-20}{17}\)+ \(\frac{17}{17}\)
= \(\frac{-3}{17}\)
Tính bằng cách hợp lý nếu có :
\(a,\frac{15}{16}:\left(\frac{1}{2}-\frac{2}{3}\right)^2\) \(b,\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-1\frac{15}{17}+\frac{2}{3}\) \(c,1\frac{4}{23}+\frac{5}{21}-\frac{4}{23}+0,5+\frac{16}{21}\) \(d,\frac{3}{4}.26\frac{2}{9}-38\frac{2}{9}.\frac{3}{4}\)