Question

tính:

a) (4-12/5).25/8-2/5:-4/25

b) (-5/24+3/4-7/12):(-5/16)

c)-5/7.2/11+-5/7.9/11

d) 6/7+5/4:(-5)-(-1/28).(-2)

Answer 1

a; (4 - \(\dfrac{12}{5}\)).\(\dfrac{25}{8}\) - \(\dfrac{2}{5}\) : - \(\dfrac{4}{25}\)

= 4.\(\dfrac{25}{8}\) - \(\dfrac{12}{5}\).\(\dfrac{25}{8}\) - \(\dfrac{2}{5}\) x \(\dfrac{-25}{4}\)

= \(\dfrac{25}{2}\) - \(\dfrac{15}{2}\) + \(\dfrac{5}{2}\)

= \(\dfrac{10}{2}\) + \(\dfrac{5}{2}\)

 = \(\dfrac{15}{2}\) 

 

 

Answer 2

b; (- \(\dfrac{5}{24}\) + \(\dfrac{3}{4}\) - \(\dfrac{7}{12}\)) : (- \(\dfrac{5}{16}\))

 = (- \(\dfrac{5}{24}\)) : (-\(\dfrac{5}{16}\)) + \(\dfrac{3}{4}\) : (- \(\dfrac{5}{16}\)) - \(\dfrac{7}{12}\) : (- \(\dfrac{5}{16}\))

= \(\dfrac{5}{24}\) x \(\dfrac{16}{5}\) - \(\dfrac{3}{4}\) x \(\dfrac{16}{5}\) + \(\dfrac{7}{12}\) x \(\dfrac{16}{5}\) 

= \(\dfrac{2}{3}\) - \(\dfrac{12}{5}\) + \(\dfrac{28}{15}\)

= \(\dfrac{10}{15}\) - \(\dfrac{36}{15}\) + \(\dfrac{28}{15}\)

= \(\dfrac{-26}{15}\) + \(\dfrac{28}{15}\)

 = \(\dfrac{2}{15}\)