`@` `\text {Ans}`
`\downarrow`
`a)`
`5/23 + 7/17 + 0,25 - 5/23 + 10/17`
`= (5/23 - 5/23) + (7/17 + 10/17) + 0,25`
`= 0 + 1 + 0,25`
`= 1,25`
`c)`
`13 1/4 \div (-4/7) - 17 1/4 \div (-4/7)`
`= 13 1/4 * (-7/4) - 17 1/4 * (-7/4)`
`= (-7/4) * (13 1/4 - 17 1/4)`
`= (-7/4) * (-4)`
`= 7`
a) \(\dfrac{5}{23}+\dfrac{7}{17}+0,25-\dfrac{5}{23}+\dfrac{10}{17}\)
\(=\left(\dfrac{5}{23}-\dfrac{5}{23}\right)+0,25+\left(\dfrac{7}{17}+\dfrac{10}{17}\right)\)
\(=0+0,25+1\)
\(=1,25=\dfrac{5}{4}\)
c) \(13\dfrac{1}{4}:\left(-\dfrac{4}{7}\right)-17\dfrac{1}{4}:\left(-\dfrac{4}{7}\right)\)
\(=\left(13\dfrac{1}{4}-17\dfrac{1}{4}\right):\left(-\dfrac{4}{7}\right)\)
\(=-4\dfrac{1}{4}:\left(-\dfrac{4}{7}\right)\)
\(=\dfrac{-16}{4}:\left(-\dfrac{4}{7}\right)\)
\(=-4:\left(-\dfrac{4}{7}\right)\)
\(=-4\cdot\left(-\dfrac{7}{4}\right)\)
\(=7\)
\(\dfrac{5}{23}+\dfrac{7}{17}+0,25-\dfrac{5}{23}+\dfrac{10}{17}\\ =\left(\dfrac{5}{23}-\dfrac{5}{23}\right)+\left(\dfrac{5}{17}+\dfrac{10}{17}\right)+\dfrac{25}{100}\\ =0+\dfrac{17}{17}+\dfrac{1}{4}\\ =1+\dfrac{1}{4}\\ =\dfrac{4}{4}+\dfrac{1}{4}\\ =\dfrac{5}{4}\\\)
\(13\dfrac{1}{4}:\left(-\dfrac{4}{7}\right)-17\dfrac{1}{4}:\left(-\dfrac{4}{7}\right)\\ =13\dfrac{1}{4}\cdot\left(-\dfrac{7}{4}\right)-17\dfrac{1}{4}\cdot\left(-\dfrac{7}{4}\right)\\ =\left(-\dfrac{7}{4}\right)\cdot\left(13\dfrac{1}{4}-17\dfrac{1}{4}\right)\\ =-\dfrac{7}{4}\cdot\left(-4\right)\\ =\dfrac{28}{4}\\ =7\)
