4.15.17+5.12.27+6.10.56

=(4.15).17+(5.12).27+(6.10).56

=60.17+60.27+60.56

=60.(17+27+56)

=60.100

=6 000

4 . 15 . 17 + 5 . 12 . 27 + 6 . 10 . 56

= ( 4 . 15 ) . 17 + ( 5 . 12 ) . 27 + ( 6 . 10 ) . 56

= 60 . 17 + 60 . 27 + 60 . 56

= 60 . ( 17 + 27 + 56 )

= 60 . 100

= 6000

tách ra bạn nhé

mik chỉ biết có thế thôi

407-{[20:4+9]:2}

407-{[5+9]:2}

407-{14:2}

407-7

400

.... ko biết

4.15.17=1020

5.12.17=1020

6.10.56=3360

4.15.17+5.12.17+6.10.56=1020+1020+3360=5400

K nhé MN?????????

Hok tốt!!!!!!!

4 . 15 . 17 + 5 . 12 . 17 + 6 . 10 . 56

= 17 . ( 4 . 15 + 5 . 12 ) + 6 . 10 . 56

= 17 . ( 60 + 60 ) + 6 . 10 . 56

= 17 . 120 + 6 . 10 . 56

= 2040 + 3360

= 5400

`@` `\text {Ans}`

`\downarrow`

`1,`

`a)`

`-7/25 + (-8)/25`

`= (-7 - 8)/25`

`= -15/25`

`= -3/5`

`b)`

`6/13 + (-15)/39`

`= 18/39 + (-15)/39`

`= (18 - 15)/39`

`= 3/39`

`= 1/13`

`c)`

`5/7 + 4/(-14)`

`= 10/14 + (-4)/14`

`= (10 - 4)/14`

`= 6/14`

`= 3/7`

`d)`

`-8/18 + (-15)/27`

`= -4/9 + (-5)/9`

`= (-4-5)/9`

`= -9/9 = -1`

`2,`

`a)`

`3/5 + (-7)/4`

`= 12/20 + (-35)/20`

`= (12 - 35)/20`

`=-23/20`

`b)`

`(-2) + (-5)/8`

`= (-16)/8 + (-5)/8`

`= (-16 - 5)/8`

`= -21/8`

`c)`

`1/8 + (-5)/9`

`= 9/72 + (-40)/72`

`= (9-40)/72`

`= -31/72`

`d)`

`6/13 + (-14)/39`

`= 18/39 + (-14)/39`

`= (18 - 14)/39`

`= 4/39`

`e)`

`(-18)/24 + 15/21`

`= (-3)/4 + 5/7`

`= (-21)/28 + 20/28`

`= (-21 + 20)/28`

`= -1/28`

Cau a la ban hay tinh trong dau ngoac don truoc sau do lam nhoac vuong va lam dau ngoac nhon va tinh cac phep tinh con lai

a:100;b:300;c:200;d:3;e:13

17.( 85+15)-120=15.100-120=1500 -120=1380

Bạn gom số lại là được nhé tick nhé

mn ơi e vít nhầm là tính rồi rút gọn mn sửa lại là rút gọn rùi tính

a: \(\dfrac{7}{4}-\dfrac{11}{8}+\dfrac{1}{2}\)

\(=\dfrac{14-11+4}{8}\)

\(=\dfrac{7}{8}\)

b: \(\dfrac{3}{16}+\dfrac{7}{30}\cdot\dfrac{40}{36}\)

\(=\dfrac{3}{16}+\dfrac{7}{36}\cdot\dfrac{40}{30}\)

\(=\dfrac{3}{16}+\dfrac{7}{36}\cdot\dfrac{4}{3}\)

\(=\dfrac{3}{16}+\dfrac{7}{27}=\dfrac{81+112}{432}=\dfrac{193}{432}\)

c: \(\left(\dfrac{9}{2}-\dfrac{15}{4}\right):\dfrac{21}{12}\)

\(=\left(\dfrac{18}{4}-\dfrac{15}{4}\right):\dfrac{7}{4}\)

\(=\dfrac{3}{4}\cdot\dfrac{4}{7}=\dfrac{3}{7}\)