Tính: 1 4 + 3 8 + 5 16
Giúp mình với ạ Bài 1 Tính 1) 2/9 + -3/4 + 5/30 2) -7/12 - 11/18 3) 7/8 - -5/16 4) 3/8 - -9/10 - 5/16
1)` 2/9 + -3/4 + 5/30= (40+(-135) + 30 )/180 = -65/180 = -13/36`
2) `-7/12 - 11/18=(-21)/36 - 22/36 = -43/36 `
3) `7/8 - (-5)/16=14/16- (-5)/16 = 19/16 `
4) `3/8 - (-9)/10 - 5/16= (30- (-72) -25)/80=77/80`
1)\(\dfrac{2}{9}+\dfrac{-3}{4}+\dfrac{5}{30}\)
\(=\dfrac{2.20}{9.20}+\dfrac{-3.45}{4.45}+\dfrac{5.6}{30.6}\)
\(=\dfrac{40}{180}+\dfrac{-135}{180}+\dfrac{30}{180}\)
\(=\dfrac{40+\left(-135\right)+30}{180}\)
\(=\dfrac{-65}{180}\)
\(=\dfrac{-13}{36}\)
2)\(\dfrac{-7}{12}-\dfrac{11}{18}\)
\(=\dfrac{-7.3}{12.3}-\dfrac{11.2}{18.2}\)
\(=\dfrac{-21}{36}-\dfrac{22}{36}\)
\(=\dfrac{-21-22}{36}\)
\(=\dfrac{-43}{36}\)
3)\(\dfrac{7}{8}-\dfrac{-5}{16}\)
\(=\dfrac{7.2}{8.2}-\dfrac{-5}{16}\)
\(=\dfrac{14}{16}-\dfrac{-5}{16}\)
\(=\dfrac{14-\left(-5\right)}{16}\)
\(=\dfrac{19}{16}\)
4)\(\dfrac{3}{8}-\dfrac{-9}{10}-\dfrac{5}{16}\)
\(=\dfrac{3.10}{8.10}-\dfrac{-9.8}{10.8}-\dfrac{5.5}{16.5}\)
\(=\dfrac{30}{80}-\dfrac{-72}{80}-\dfrac{25}{80}\)
\(=\dfrac{30-\left(-72\right)-25}{80}\)
\(=\dfrac{77}{80}\)
2 tính : a) 1+1/4+1/8+1/16 =
=
b) 2-1/8-1/12-1/16 =
=
c) 4/99 x 18/5 : 12/11 + 3/5 =
=
d) ( 1-3/4 ) x ( 1+ 1/3 ) : ( 1- 1/3 ) =
=
a) 1 + 1/4 + 1/8 + 1/16
= 16/16 + 4/16 + 2/16 + 1/16
= 23/16
b) 2 - 1/8 - 1/12 - 1/16
= 96/48 - 6/46 - 4/48 - 3/48
= 83/48
c) 4/99 × 18/5 : 12/11 + 3/5
= 8/55 : 12/11 + 3/5
= 2/15 + 3/5
= 2/15 + 9/15
= 11/15
d) (1 - 3/4) × (1 + 1/3) : (1 - 1/3)
= 1/4 × 4/3 : 2/3
= 1/3 : 2/3
= 2
1 + 1/4 + 1/8 + 1/16
= 16 + 4 + 2 + 1 / 16
=23/16
2-1/8-1/12-1/16
= 96 - 6 - 4 - 3 / 48
= 83 / 48
4/99 x 18/5 : 12 /11 + 3/5
= 4/99 x 18/5 x 11/12 + 3/5
= 2/15 + 3/5
= 11/15
(1 - 3/4) x (1+1/3) : (1-1/3)
= 1/4 x 4/3 : 2/3
= 1/4 x 4/3 x 3/2
= 1/2
tính nhanh p/s 1+ 5/4 + 5/8 + 5/16 + 5/32 + 5/64
b) 1/3 +1/9 + 1/27 + 1/81 +...........+ 1/59049
c) 3/2 + 3/8 + 3/32 +3/128 + 3/512
d) 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256 giúp mình với
b: A=1/3+1/9+...+1/3^10
=>3A=1+1/3+...+1/3^9
=>A*2=1-1/3^10=(3^10-1)/3^10
=>A=(3^10-1)/(2*3^10)
c: C=3/2+3/8+3/32+3/128+3/512
=>4C=6+3/2+...+3/128
=>3C=6-3/512
=>C=1023/512
d: A=1/2+...+1/256
=>2A=1+1/2+...+1/128
=>A=1-1/256=255/256
Kết quả phép tính 3/4 - 2/4 là :
→❤_ 1/4 5/8 6/16 5/16 _❤←
1. Phân Số gấp 4 lần phân số 3/8 1... 2. Tính giá trị biểu thức: 9/16 - 3/16 : 3/8 3. Tìm X: 3/5 : x = 3 4. Tính: 1/5 + 4/11 + 4/5 + 7/11 ; 5/6 + ( 5/9 - 1/4 ) 5. Tổng hai số bằng số nhỏ nhất có ba chữ số, số bé bằng 2/3 số lớn. Tìm hai số đó
3:
3/5:x=3
=>x=3/5:3=1/5
4:
a:
=1/5+4/5+4/11+7/11=1+1=2
b: =5/6+5/9-1/4
=30/36+20/36-9/36
=41/36
5: Tổng hai số là 100
Số bé là 100*2/5=40
Số lớn là 100-40=60
Tính :
2/5 + 11/15 =
7/8 - 7/9 =
11/13 x 26/31 =
16/24 : 4 =
30 : 6/5 =
9/16 : 4 =
1/2 : 1/3 x 8/15 =
\(\dfrac{2}{5}+\dfrac{11}{15}=\dfrac{6}{15}+\dfrac{11}{15}=\dfrac{17}{15}\)
\(\dfrac{7}{8}-\dfrac{7}{9}=\dfrac{63}{72}-\dfrac{56}{72}=\dfrac{7}{72}\)
\(\dfrac{11}{13}\times\dfrac{26}{31}=\dfrac{22}{31}\)
\(\dfrac{16}{24}:4=\dfrac{16}{24}\times\dfrac{1}{4}=\dfrac{4}{24}=\dfrac{1}{6}\)
\(30:\dfrac{6}{5}=30\times\dfrac{5}{6}=25\)
\(\dfrac{9}{16}:4=\dfrac{9}{16}\times\dfrac{1}{4}=\dfrac{9}{64}\)
\(\dfrac{1}{2}:\dfrac{1}{3}\times\dfrac{8}{15}=\dfrac{1}{2}\times3\times\dfrac{8}{15}=\dfrac{4}{5}\)
2/5 + 11/15 = 17/15
7/8 - 7/9 = 7/72
11/13 x 26/31 = 22/31
16/24 : 4 = 1/6
30 : 6/5 = 25
9/16 : 4 = 9/64
1/2 : 1/3 x 8/15 = 3/2 x 8/15 = 4/5
Câu 1. Tính :
7/4 : 8/3 =
7/6 : 21/4 =
8/ 5 : 16/7 =…
5/12 : 25/4 =
\(\dfrac{7}{4}:\dfrac{8}{3}=\dfrac{21}{32}\)
\(\dfrac{7}{6}:\dfrac{21}{4}=\dfrac{28}{126}\)
\(\dfrac{8}{5}:\dfrac{16}{7}=\dfrac{56}{80}\)
\(\dfrac{5}{12}:\dfrac{25}{4}=\dfrac{20}{300}\)
Có gì you tự rút gọn nha :>
Dạng 1. Thực hiện phép tính (tính nhanh nếu có thể)
a) 1/2 + 3/4 - (3/4 - 4-5)
b) (9/16 + 8/-27) - (19/27 - 7/16 - 2)
c) - 5/8 . (4/9 + 7/-12)
d) 7/10 . -3/5 + 7/10 . -2/5 - -3/10
e) -3/7 . 5/9 + 4/9 . -3/7 + 2 3/7
f) 8 2/7 - (3 4/9 + 4 2/7)
h) 3 . (-1/2 )^2 - (4/5 + 8/15) : 5/6
các bạn giúp mình nha!!
a) 1/2 + 3/4 - (3/4 - 4 - 5)
= 1/2 + 3/4 - 3/4 + 4 + 5
= (3/4 - 3/4) + (4 + 5) + 1/2
= 0 + 9 + 1/2
= 19/2
b) [9/16 + 8/(-27)] - (19/27- 7/16 - 2)
= 9/16 - 8/27 - 19/27 + 7/16 + 2
= (9/16 + 7/16) + (-8/27 - 19/27) + 2
= 1 - 1 + 2
= 2
c) -5/8 . [4/9 + 7/(-12)]
= -5/8 . (-5/36)
= 25/288
d) 7/10 . (-3/5) + 7/10 . (-2/5) - (-3/10)
= 7/10 . (-3/5 - 2/5) + 3/10
= 7/10 . (-1) + 3/10
= -2/5
e) -3/7 . 5/9 + 4/9 . (-3/7) + 2 3/7
= -3/7 . (5/9 + 4/9) + 17/7
= -3/7 . 1 + 17/7
= 2
f) 8 2/7 - (3 4/9 + 4 2/7)
= 8 + 2/7 - 3 - 4/9 - 4 - 2/7
= (8 - 3 - 4) + (2/7 - 2/7) - 4/9
= 1 - 4/9
= 5/9
h) 3.(-1/2)² - (4/5 + 8/15) : 5/6
= 3.1/4 - 4/3 : 5/6
= 3/4 - 8/5
= -17/20
Câu 1. Tính rồi gút gọn
7/4 : 8/3 =
7/6 : 21/4 =
8/ 5 : 16/7 =…
5/12 : 25/4 =
7/4 : 8/3 = 7/4 x 3/8 = 21/32
7/6 : 21/4 = 7/6 x 4/21= 2/9
8/ 5 : 16/7 = 8/5 x 7/16 = 7/10
5/12 : 25/4 = 5/12 x 4/24 = 1/15
tính
a) 0+1+2+3+4+5+8+....+89
b)1+4+9+16+......+100
c)2+4+8+16+.........+1024