1+2+4+5+6+7+3+5+7+5+5+2+23+65+65+7+7+7+7+7=?
9+2+5+3+7+8+4+7+4+7+2+4+2+9+6+4+65+6+7+4+6+4+6+3+7+4+8+5+9+08+87+1+2+3+4+2+3+2+5+6+767+5+75+6+4+6+5+66+5+7+546+46+43+6+3+6+4+6+7+8878+68+68+6+7+9+9
\(9+2+5+3+7+8+4+2+9+6+4+65+6+7+4+6+3+7+4+8+5+9+08+87+1+2+3+4+2+3+2+5+6+767+5+75+6+4+6+5+66+5+7+546+46+43+6+3+6+4+6+7+8878+68+68+6+7+9+9=10961\)
Thực hiện phép tính:
4, 2/7+ 1/9+ 3/7+ 5/9+ -5/6
5, -5/7+ 3/4+ -1/5+ -2/7+ 1/4
6, -3/31+ -6/17+ 1/25+ -28/31+ -1/17+ -1/5
4: \(=\dfrac{2+3}{7}+\dfrac{1+6}{9}-\dfrac{5}{6}=\dfrac{5}{7}+\dfrac{7}{9}-\dfrac{5}{6}=\dfrac{83}{126}\)
5: \(=\dfrac{-5-2}{7}+\dfrac{3+1}{4}-\dfrac{1}{5}=-\dfrac{1}{5}\)
6: \(=\dfrac{-3-28}{31}+\dfrac{-6-1}{17}+\dfrac{1-5}{25}=-1-\dfrac{7}{17}-\dfrac{4}{25}=-\dfrac{668}{425}\)
Thực hiện phép tính:
4, 2/7+ 1/9+ 3/7+ 5/9+ -5/6
5, -5/7+ 3/4+ -1/5+ -2/7+ 1/4
6, -3/31+ -6/17+ 1/25+ -28/31+ -1/17+ -1/5
4. \(\dfrac{2}{7}+\dfrac{1}{9}+\dfrac{3}{7}+\dfrac{5}{9}+\dfrac{-5}{6}\)
\(=\left(\dfrac{2}{7}+\dfrac{3}{7}\right)+\left(\dfrac{1}{9}+\dfrac{5}{9}\right)+\dfrac{-5}{6}\)
\(=\dfrac{5}{7}+\dfrac{2}{3}+\dfrac{-5}{6}\)
\(=\dfrac{30+28+\left(-35\right)}{42}=\dfrac{23}{42}\)
5. \(\dfrac{-5}{7}+\dfrac{3}{4}+\dfrac{-1}{5}+\dfrac{-2}{7}+\dfrac{1}{4}\)
\(=\left(\dfrac{-5}{7}+\dfrac{-2}{7}\right)+\left(\dfrac{3}{4}+\dfrac{1}{4}\right)+\dfrac{-1}{5}\)
\(=\dfrac{-7}{7}+\dfrac{4}{4}+\dfrac{-1}{5}\)
\(=-1+1+\dfrac{-1}{5}\)
\(=-\dfrac{1}{5}\)
6. \(\dfrac{-3}{31}+\dfrac{-6}{17}+\dfrac{1}{25}+\dfrac{-28}{31}+\dfrac{-1}{17}+\dfrac{-1}{5}\)
\(=\left(\dfrac{-3}{31}+\dfrac{-28}{31}\right)+\left(\dfrac{-6}{17}+\dfrac{-1}{17}\right)+\dfrac{1}{25}+\dfrac{-1}{5}\)
\(=\dfrac{-31}{31}+\dfrac{-7}{17}+\dfrac{1}{25}+\dfrac{-1}{5}\)
\(=-1+\dfrac{-7}{17}+\dfrac{1}{25}+\dfrac{-1}{5}\)
\(=\dfrac{-425+\left(-175\right)+17+\left(-85\right)}{425}=\dfrac{-668}{425}\)
Thực hiện phép tính:
4, 2/7+ 1/9+ 3/7+ 5/9+ -5/6
5, -5/7+ 3/4+ -1/5+ -2/7+ 1/4
6, -3/31+ -6/17+ 1/25+ -28/31+ -1/17+ -1/5
Tìm giá trị lớn nhất , nhỏ nhất của
1) D=3- 3/5 . |2/5 - x|
2) E=7/23 + 3/7 . |x - 4/7|
3) F=|x - 5| -|x - 7|
4) G= |500 - x| + |x - 300|
5) H=|125 - x| + |x - 65|
4) so sánh hai phân số sau
a) 7/15 và 4/9
B1 tính nhanh nếu có thể
a) (-18).5+5.10+5.(-2)
b) (-15):(-5)+7.(-3/7)
c) (-157)+(-16)+257+(-43)+(-84)
d) (+23)+(-135)-(-77)-/-65/+(-30)
e) -5/7 + (-6/11+1)
f) 1/2-2/3+4/5-5/6
g)1/3.4/5+1/3.6/5+2/3
h) -5/7.2/11+-5/7.9/11+1 5/7 không phải 15 phần 7
I)19/5.2007/2017+19/5.10/2017
K) 4/25.5/9+-4/25.10/3+7/9
m) 7/19.8/11+7/19.3/11+12/19
n)17/13.18/23-4/13.18/23-(-5)/23
P) 5/7 .5/11+5/7.2/11-5/7.14/11
q)-2/17+15/19+-15/17+13/20+4/19
X)7/-25+-18/25+4/23+5/8+19/23
S)5/7.-4/19+-15/7.5/19
tính nhanh
11211-1-1-1-2-2-2-2-3-3-3-4-4-4-5-5-5-6-7-7-65-4-3-2-34-5-3-3-4
11211 - 1 - 1 - 1 - 2 - 2 - 2 - 2 - 3 - 3 - 3 - 4 - 4 - 4 - 5 - 5 - 5 - 6 - 7 - 7 - 65 - 4 - 3 - 2 - 34 - 5 - 3 - 3 - 4
= 11211 - (1 + 1 + 1 + 2 + 2 + 2 + 2 + 3 + 3 + 3 + 4 + 4 + 4 + 5 + 5 + 5 + 6 + 7 + 7 + 65 + 4 + 3 + 2 + 34 + 5 + 3 + 3 + 4)
= 11211 - 190
= 11021
1+2+3+4+5+6+7+8+9+0+1+2+3+4+5+6+7+8+9+9+8+7+6+5+4+3+2+1+1+34+4+6+7+8+97+6+4+3+32+4+57+7+8+8+6+65+4+3+3+46+7+8+7+64+3+3+5+68+8+6+3+3+5+78+8+6+54+5+7+8+852+3+5+89+8+5+45+7×9×9×9×9×9×9×9×9×9×9×9×8×8×7×9×9×7×7×87×7×8×7×7×8×7×7×8
7/3 + 13/3=
65/7 + 38/7=
103/10 - 47/10=
7/3 nhan 21/4=
17/5 nhan 15/7=
15/6 ; 5/2=
5/8 - 2/5
11/10 - 3/4
2/3+1/2-5/6=
giup mik voi mik ko biet lam may cau nay
\(\frac{7}{3}+\frac{13}{3}=\frac{7+13}{3}=\frac{20}{3}\)
\(\frac{65}{7}+\frac{38}{7}=\frac{65+38}{7}=\frac{103}{7}\)
\(\frac{103}{10}-\frac{47}{10}=\frac{103-47}{10}=\frac{56}{10}=\frac{28}{5}\)
\(\frac{7}{3}\times\frac{21}{4}=\frac{7\times21}{3\times4}=\frac{147}{12}=\frac{49}{4}\)