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4:
a: =4/15-2,9+11/15=1-2,9=-1,9
b: \(=-36,75+3,7-63,25+6,3=10-100=-90\)
c: \(=6,5+3,5-\dfrac{10}{17}-\dfrac{7}{17}=10-1=9\)
d: \(=\dfrac{13}{25}\left(-39,1-60,9\right)=\dfrac{13}{25}\left(-100\right)=-52\)
e: =-5/12-7/12-3,7-6,3=-1-10=-11
f: =2,8(-6/13-7/13)-7,2=-2,8-7,2=-10
`@` `\text {Ans}`
`\downarrow`
`a.`
`A=(1/2-7/13-1/3)+(-6/13+1/2+1 1/3)`
`= 1/2 - 7/13 - 1/3 - 6/13 + 1/2 + 1 1/3`
`= (1/2 + 1/2) + (-7/13 - 6/13) + (-1/3 + 1 1/3) `
`= 1 - 1 + 1`
`= 1`
`b.`
`B=0,75+2/5+(1/9-1 1/2+5/4)`
`= 3/4 + 2/5 + 1/9 - 3/2 + 5/4`
`= (3/4+5/4)+ 1/9 + 2/5 - 3/2`
`= 2 + 1/9 - 11/10`
`= 19/9 - 11/10`
`= 91/90`
`c.`
`(-5/9).3/11+(-13/18).3/11`
`= 3/11*[(-5/9) + (-13/18)]`
`= 3/11*(-23/18)`
`= -23/66`
`d.`
`(-2/3).3/11+(-16/9).3/11`
`= 3/11* [(-2/3) + (-16/9)]`
`= 3/11*(-22/9)`
`= -2/3`
`e.`
`(-1/4).(-2/13)-7/24.(-2/13)`
`= (-2/13)*(-1/4-7/24)`
`= (-2/13)*(-13/24)`
`= 1/12`
`f.`
`(-1/27).3/7+(5/9).(-3/7)`
`= 3/7*(-1/27 - 5/9)`
`= 3/7*(-16/27)`
`= -16/63`
`g.`
`(-1/5+3/7):2/11+(-4/5+4/7):2/11`
`=[(-1/5+3/7)+(-4/5+4/7)] \div 2/11`
`= (-1/5+3/7 - 4/5 + 4/7) \div 2/11`
`= [(-1/5-4/5)+(3/7+4/7)] \div 2/11`
`= (-1+1) \div 2/11`
`= 0 \div 2/11 = 0`
a: \(=\dfrac{2}{3}-\dfrac{2}{5}=\dfrac{10-6}{15}=\dfrac{4}{15}\)
b: \(=\dfrac{9}{12}-\dfrac{10}{12}+\dfrac{11}{12}=\dfrac{10}{12}=\dfrac{5}{6}\)
c: \(=\dfrac{1}{4}-\dfrac{3}{2}+\dfrac{1}{2}\cdot\dfrac{12}{5}+\dfrac{1}{20}=\dfrac{-5}{4}+\dfrac{6}{5}+\dfrac{1}{20}=0\)
d: \(=\dfrac{1}{25}\cdot\dfrac{20}{15}+\left(\dfrac{1}{4}-\dfrac{5}{6}\right):\dfrac{14}{3}=-\dfrac{43}{600}\)
\(\frac{2}{3}\cdot x-\frac{1}{4}\left(1\frac{1}{3}-\frac{3}{4}\right)=0,25\cdot\frac{2}{3}\)
\(\Rightarrow\frac{2}{3}\cdot x-\frac{1}{4}\left(\frac{4}{3}-\frac{3}{4}\right)=\frac{1}{4}\cdot\frac{2}{3}\)
\(\Rightarrow\frac{2}{3}\cdot x-\frac{1}{4}\cdot\frac{7}{12}=\frac{1}{6}\)
\(\Rightarrow\frac{2}{3}.x-\frac{7}{48}=\frac{1}{6}\)
\(\Rightarrow\frac{2}{3}x=\frac{5}{16}\)
\(\Rightarrow x=\frac{15}{32}\)
\(\frac{2}{3}\times x-\frac{1}{4}:\left(1\frac{1}{3}-\frac{3}{4}\right)=0,25\times\frac{2}{3}\)
\(\frac{2}{3}\times x-\frac{1}{4}:\left(\frac{4}{3}-\frac{3}{4}\right)=\frac{1}{4}\times\frac{2}{3}\)
\(\frac{2}{3}\times x-\frac{1}{4}:\frac{7}{12}=\frac{1}{6}\)
\(\frac{2}{3}\times x-\frac{3}{7}=\frac{1}{6}\)
\(\frac{2}{3}\times x=\frac{1}{6}+\frac{3}{7}\)
\(\frac{2}{3}\times x=\frac{25}{42}\)
\(x=\frac{25}{42}:\frac{2}{3}\)
\(x=\frac{25}{28}\)