2/8 + 14/7 =
Điền dấu (>,<,=) thích hợp vào chỗ chấm:
8 + 7…14 8 + 5…14 |
8 + 6…7 + 8 8 + 4…9 + 4 |
9 + 6…6 + 9 9 + 2…2 + 9 |
|
8 + 7 > 14 8 + 5 < 14 |
8 + 6 < 7 + 8 8 + 4 < 9 + 4 |
9 + 6 = 6 + 9 9 + 2 = 2 + 9 |
|
tính nhanh 5/14 x 2/9 + 5/14 + 5/14 x 7/9, 6/8 : 7/6 - 6/8 : 1/6
a: \(=\dfrac{5}{14}\left(\dfrac{2}{9}+\dfrac{7}{9}+1\right)=\dfrac{5}{14}\cdot2=\dfrac{5}{7}\)
b: \(=\dfrac{6}{8}\left(\dfrac{6}{7}-6\right)=\dfrac{6}{8}\cdot\dfrac{-36}{7}=\dfrac{-216}{56}=\dfrac{-27}{7}\)
tính các phân số sau 10/4 , 10/9, 9/8, 2/7
9/8 và 10/9, 10/14 và 2/7 , 9/8 và 2/7, 10/14 và 10/9 8h31 nộp ạ
mik quên số nào lớn hơn 1
Đặt tính rồi tính (theo mẫu)
+ 9 chia 4 được 2, viết 2
2 nhân 2 bằng 8; 9 trừ 8 bằng 1
+ Hạ 4, được 14; 14 chia 4 được 3, viết 3.
3 nhân 4 bằng 12; 14 trừ 12 bằng 2
+ Hạ 8, được 28, 28 chia 4 được 7, viết 7.
7 nhân 4 bằng 28; 28 trừ 28 bằng 0
630 : 7
Tính :
a) 7 x \(\dfrac{3}{14}\) - \(\dfrac{1}{14}\) b) \(\dfrac{3}{2}\) + \(\dfrac{7}{4}\) x \(\dfrac{2}{5}\)
c) \(\dfrac{9}{8}\) : 3 + \(\dfrac{7}{8}\) : 3 d) 2 : \(\dfrac{3}{4}\) - \(\dfrac{5}{8}\) x \(\dfrac{4}{3}\)
`7 xx 3/14 -1/14`
`= 21/14 -1/14`
`= 20/14`
`=10/7`
__
`3/2 + 7/4 xx 2/5`
`= 3/2 + 14/20`
`= 3/2 + 7/10`
`= 15/10 +7/10`
`= 23/10`
__
`9/8 : 3 + 7/3 : 3`
`= 9/8 xx 1/3 + 7/3 xx 1/3`
`=1/3 xx ( 9/8 + 7/3)`
`= 1/3 xx 83/24`
`= 83/72`
__
`2 : 3/4 - 5/8 xx 4/3`
`= 2 xx 4/3 - 5/8 xx 4/3`
`= 4/3 xx ( 2-5/8)`
`= 4/3 xx ( 16/8 -5/8)`
`= 4/3 xx 11/8`
`= 44/24`
`=11/6`
` @ \color{Red}{sushiteam}`
4/7 + 2/8 =
8/6 - 8/24 =
9/28 x 14/9 =
7/6 : 2/3 =
a) \(\dfrac{4}{7}+\dfrac{2}{8}=\dfrac{32}{56}+\dfrac{14}{56}=\dfrac{46}{56}=\dfrac{23}{28}\)
b) \(\dfrac{8}{6}-\dfrac{8}{24}=\dfrac{32}{24}-\dfrac{8}{24}=\dfrac{24}{24}=1\)
c) \(\dfrac{9}{28}\times\dfrac{14}{9}=\dfrac{126}{252}=\dfrac{1}{2}\)
d) \(\dfrac{7}{6}\div\dfrac{2}{3}=\dfrac{7}{6}\times\dfrac{3}{2}=\dfrac{21}{12}\)
1. \(\dfrac{4}{7}+\dfrac{2}{8}=\dfrac{32}{56}+\dfrac{14}{56}=\dfrac{32+14}{56}=\dfrac{46}{56}=\dfrac{23}{28}\)
2. \(\dfrac{8}{6}-\dfrac{8}{24}=\dfrac{32}{24}-\dfrac{8}{24}=\dfrac{32-8}{24}=\dfrac{24}{24}=1\)
3. \(\dfrac{9}{28}\text{×}\dfrac{14}{9}=\dfrac{9\text{×}14}{28\text{×}9}=\dfrac{126}{252}=\dfrac{7}{14}\)
4. \(\dfrac{7}{6}:\dfrac{2}{3}=\dfrac{7}{6}\text{×}\dfrac{3}{2}=\dfrac{7\text{×}3}{6\text{×}2}=\dfrac{21}{12}=\dfrac{7}{4}\)
(-5) + (-7) + (-8) + (-3) =
(-4)+((-2)+(-5)+(-6)=
(-8)+(-11)+(-4)+(-2)=
(-9)+((-15)+(-6)+(-3)=
(-12)+(-9)+(-3)+(-8)=
(+3)+(+11)+(+14)+(+7)=
(+9)+(+5)+(+14)+(+2)=
(+12)+(+10)+(+3)+(+5)=
(+4)+(+7)+(+12)+(+15)=
(+20)+(+14)+(+3)+(+7)=
ai lam minh tick cho
a: =-5-7-8-3=-26
b: =-4-2-5-6=-17
c: =-8-11-4-2=-25
d: -9-15-6-3=-30
e: =-12-9-3-8=-32
bài 1. Tính
a) 7/-25 + -8/25 b) 6/13 + -15/39 c) 5/7 + 4/-14 d) -8/18 + -15/27
bài 2. Tính
a) 3/5 + -7/4 b) (-2) + -5/8 c) 1/8 + -5/9 d) 6/13 + -14/39 e) -18/24 + 15/21
`@` `\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`
(√28 -2 √14 + √7) √7 +7 √ 8
\(\left(\sqrt{28}-2\sqrt{14}+\sqrt{7}\right)\cdot\sqrt{7}+7\sqrt{8}\)
\(=\left(3\sqrt{7}-2\sqrt{14}\right)\cdot\sqrt{7}+14\sqrt{2}\)
\(=21\)
( ^28 - 2^14 +^7 ) ^ 7 + 7^8
= ( ^ 4.7 - 2^14 + ^7 ) ^7 + 7^4.2
= ( 2^7 - 2^14 + ^7 ) ^7 + 7.2^2
= ( 3^7 - 2^14 ) ^7 + 14^2
= 21 - 14^2 + 14^2
= 21
1/2+2/3+3/4+4/5+5/6+6/7+7/8+8/9+9/10+10/11+11/12+12/13+13/14+14/15=?