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x = 5/4 - 2/3
x = 7/12
a) \(x+\dfrac{4}{5}=\dfrac{45}{5}-\left(\dfrac{3}{7}+\dfrac{3}{5}\right)\)
\(x+\dfrac{4}{5}=\dfrac{45}{5}-\dfrac{36}{35}\)
\(x+\dfrac{4}{5}=\dfrac{279}{35}\)
\(x=\dfrac{279}{35}-\dfrac{4}{5}\)
\(x=\dfrac{251}{35}\)
b) \(\dfrac{5}{8}\times x=\dfrac{4}{5}\)
\(x=\dfrac{4}{5}\div\dfrac{5}{8}\)
\(x=\dfrac{32}{25}\)
a)
= 5/27 + 2/3
= 5/27 + 18/27
= 23/27
b)
= 28/7 - 3/7
= 257
c)
= 14/168
= 1/12
d)
= 3/7 x 1/4
= 3/28
a)
= 5/27 + 2/3
= 5/27 + 18/27
= 23/27
b)
= 28/7 - 3/7
= 257
c)
= 14/168
= 1/12
d)
= 3/7 x 1/4
= 3/28
\(a,\dfrac{7}{12}+\dfrac{3}{4}\times\dfrac{2}{9}=\dfrac{7}{12}+\dfrac{1}{6}=\dfrac{7}{12}+\dfrac{2}{12}=\dfrac{9}{12}=\dfrac{3}{4}\)
\(b,\dfrac{8}{9}-\dfrac{4}{15}:\dfrac{2}{5}=\dfrac{8}{9}-\dfrac{4}{15}\times\dfrac{5}{2}=\dfrac{8}{9}-\dfrac{2}{3}=\dfrac{8}{9}-\dfrac{6}{9}=\dfrac{2}{9}\)
a)\(\left(\dfrac{4}{6}+\dfrac{14}{6}\right)+\left(\dfrac{7}{13}+\dfrac{19}{13}\right)+\left(\dfrac{17}{9}+\dfrac{1}{9}\right)=\dfrac{18}{6}+\dfrac{26}{13}+\dfrac{18}{9}=3+2+2=7\)
b)\(\dfrac{6}{7}+\left(\dfrac{2}{1}-\dfrac{6}{7}\right)=\dfrac{6}{7}+\left(\dfrac{14}{7}-\dfrac{6}{7}\right)=\dfrac{6}{7}+\dfrac{8}{7}=\dfrac{14}{7}=2\)
c)\(\dfrac{2}{3}\times\left(\dfrac{15}{19}+\dfrac{4}{19}\right)=\dfrac{2}{3}\times\dfrac{19}{19}=\dfrac{2}{3}\times1=\dfrac{2}{3}\)
a)(46+146)+(713+1913)+(179+19)=186+2613+189=3+2+2=7(46+146)+(713+1913)+(179+19)=186+2613+189=3+2+2=7
b)67+(21−67)=67+(147−67)=67+87=147=267+(21−67)=67+(147−67)=67+87=147=2
c)