Question

Tính:  a) 1,4 . \(\dfrac{15}{49}-\left(\dfrac{4}{5}+\dfrac{2}{3}\right):2\dfrac{1}{5}\)    

b) 3,2 . \(\dfrac{-15}{64}-\left(0,8-\dfrac{34}{15}\right):\dfrac{11}{3}\)     

c) \(\dfrac{-4}{7}.\dfrac{2}{9}-1\dfrac{3}{7}+\dfrac{-4}{7}.\dfrac{7}{9}+3\)      d) \(\dfrac{18}{37}+\dfrac{1}{3}-1\dfrac{3}{5}+\dfrac{19}{37}+\dfrac{2}{3}\) 

e) 10\(\dfrac{1}{5}-5\dfrac{1}{2}.\dfrac{60}{11}+3:15\%\)

Answer 1

`a)1,4 xx 15/49 - (4/5 + 2/3) : 2 1/5`

`=1,4 xx 15/49 - (4/5 + 2/3) : 11/5`

`=1,4 xx 15/49 - ( 12/15 + 10/15) : 11/5`

`=1,4 xx 15/49 - 22/15 : 11/15`

`=7/5 xx 15/49 - 22/15 xx 15/11`

`= 3/7 - 2/3`

`= 9/21 - 14/21`

`=-5/21`

`b) (-3,2) . -15/64+ (0,8 - 34/15) : 11/3`

`=  45/128 +  (-22/15) :11/3 `

`=  45/128 -2/5 = -31/640

`d) -4/7 . 2/9 - 1 3/7 + (-4/7) . 7/9 +3`

`= -4/7 .(2/9 +7/9) - 1 3/7+3`

`= -4/7 .1 +11/7`

`= 7/7=1`

`d) 18/37 + 1/3 + 1 2/5 + 19/37 + 2/3`

`= ( 18/37 + 19/37 ) + ( 1/3 + 2/3 ) + 7/5`

`= 1 + 1 + 7/5`

`= 17/5`

`e)``10 1/5-5 1/2*60/11+3:15%`

`=51/5-11/2*60/11+3:3/20`

`=51/5-30+3*20/3`

`=51/5-150/5+20`

`=(51-150)/5+100/5`

`=(51-150+100)/5`

`=1/5`

Answer 2

a)

=\(\dfrac{7}{5}\)x\(\dfrac{15}{49}\)-(\(\dfrac{12}{15}\)+\(\dfrac{10}{15}\)):\(\dfrac{11}{5}\)

=\(\dfrac{3}{7}\)-\(\dfrac{22}{15}\):\(\dfrac{11}{5}\)

=\(\dfrac{3}{7}\)-\(\dfrac{22}{15}\)x\(\dfrac{5}{11}\)

=\(\dfrac{3}{7}\)-\(\dfrac{2}{3}\)

=\(\dfrac{9}{21}\)-\(\dfrac{14}{21}\)

=\(\dfrac{-5}{21}\)

b)

=\(\dfrac{-32}{10}\)x\(\dfrac{-15}{64}\)+(\(\dfrac{8}{10}\)-\(\dfrac{34}{15}\)):\(\dfrac{11}{3}\)

=\(\dfrac{3}{4}\)+\(\dfrac{-22}{15}\):\(\dfrac{11}{3}\)

=\(\dfrac{3}{4}\)+\(\dfrac{-22}{15}\)x\(\dfrac{3}{11}\)

=\(\dfrac{3}{4}\)+\(\dfrac{-2}{5}\)

=\(\dfrac{15}{20}\)-\(\dfrac{8}{20}\)

=\(\dfrac{7}{20}\)