Tính nhanh
321 + { -15 + [ 30 + ( - 321)] }
( 2016 + 432 ) + ( 168 + ( - 2016)
14-(-15)-21
321+{-15+[30+(-321)]}
(2016+432)+[168+(-2016)]
\(\text{14-(-15)-21}\)
\(=14+15-21\)
\(=29-21\)
\(=8\)
\(321+\left\{-15+\left[30+\left(-321\right)\right]\right\}\)
\(=321+\left(-15\right)+30+\left(-321\right)\)
\(=\left(321+\left(-321\right)\right)+\left(\left(-15\right)+30\right)\)
\(=0+15\)
\(=15\)
\(\text{(2016+432)+[168+(-2016)]}\)
\(=2016+432+168+\left(-2016\right)\)
\(=\left[2016+\left(-2016\right)\right]+\left(432+168\right)\)
\(=0+600\)
\(=600\)
học tốt
Tinh nhanh :
a, 321 + { 15 + [ 30 + (-321) ] }
b, ( 2016 + 432 ) + [ 168 + (-2016) ]
a)=321+15+30+(-321)
=[321+(-321)]+(15+30)
=0+45=45
b)=2016+432+168+(-2016)
=[2016+(-2016)]+(432+168)
=0+600=600
a)321+{15+[30+(-321)]}=[321+(-321)]+(15+30)=0+45=45
b)(2016+432)+[168+(-2016)]=[2016+(-2016)]+(432+168)=0+600=600
bài 1
a) 321 + { ( -15) + [ 30 + ( -321 )]
b) (2016 + 432) + [ 168 + ( -2016)
ghi cách giải giúp mình nha
giải luôn giúp mình được không?
a)
= 321 + { ( -15) + (-291)}
= 321 + (-306)
= 15
b)
= (2016 + 432) + (-1848)
= 2448 + (-1848)
= 600
Tính nhanh
a . 321 + ( − 15 ) + [ 30 + ( − 321 ) ] b . ( 2018 + 432 ) + [ 168 + ( − 2018 ) ]
B1 : Tính nhanh
( 2016 + 432 ) + [ 168 + ( - 2016 ) ]
( 2016 + 432 ) + [ 168 + ( - 2016 ) ]
=2016 +432+168+(-2016)
=[2016+(-2016)] +(432+168)
= 600
(2016+432)+[168+(- 2016)]
=2016+432+168+-2016
=(-2016+2016)+(432+168)
=0+600
=600
hoc tot cho 1 nha
1)tính
a)321+{-15+[30+-321]}
b)(2016+332)+[168+-2016]
2)tìm X
a)x+7=-12
b)x-15=-21
3)tìm X
a)17-(2+x)=3
b)(6+x)-(17-21)=-25
c)-10-(31-x)=40
4)tìm X
a)15-(3+x)=4
b)(7+x)-(21-13)=32
c)-11-(19-x)=50
5)tìm X
a)5-lxl=1
b)10+lx-1l=4
6)tìm X
a)lx+4l<5
b)l3-xl>2
(l và l là giá trị tuyệt đối; những số có dấu"-"là số âm nhé)
GIÚP MÌNH VỚI ^-^
Tính A= 1/20+1/30+1/42+1/56+...+1/990
Tính S= 1/6+1/66+1/176+1/336+...+1/496*501
So sánh A và B :
A=2016^2016+2/2016^2016-1 và B=2016^2016/2016^2016-3
Baifi 1: Tính:
P= \(\dfrac{3^{2016}-6^{2016}+9^{2016}-12^{2016}+15^{2016}-18^{2016}}{-1^{2016}+2^{2016}-3^{2016}+4^{2016}-5^{2016}+6^{2016}}\)
\(P=\frac{3^{2016}-6^{2016}+9^{2016}-12^{2016}+15^{2016}-18^{2016}}{-1^{2016}+2^{2016}-3^{2016}+4^{2016}-5^{2016}+6^{2016}}\)
\(=\frac{\left(1.3\right)^{2016}-\left(2.3\right)^{2016}+\left(3.3\right)^{2016}-\left(4.3\right)^{2016}+\left(5.3\right)^{2016}-\left(6.3\right)^{2016}}{-1^{2016}+2^{2016}-3^{2016}+4^{2016}-5^{2016}+6^{2016}}\)
\(=\frac{1^{2016}.3^{2016}-2^{2016}.3^{2016}+3^{2016}.3^{2016}-4^{2016}.3^{2016}+5^{2016}.3^{2016}-6^{2016}.3^{2016}}{-1^{2016}+2^{2016}-3^{2016}+4^{2016}-5^{2016}+6^{2016}}\)
\(=\frac{-3^{2016}\left(-1^{2016}+2^{2016}-3^{2016}+4^{2016}-5^{2016}+6^{2016}\right)}{-1^{2016}+2^{2016}-3^{2016}+4^{2016}-5^{2016}+6^{2016}}\)
\(=-3^{2016}\)
giúp mình với các bạn ơi
tính S=\(\frac{2016}{5}+\frac{2016}{10}+\frac{2016}{30}+.......+\frac{2016}{47530}+\frac{2016}{48150}\)
Ta có \(S=\frac{2016}{5}+\frac{2016}{10}+\frac{2016}{30}+...+\frac{2016}{47530}+\frac{2016}{48150}\)
\(=\frac{2016}{5}.\left(\frac{1}{1}+\frac{1}{2}+\frac{1}{6}+...+\frac{1}{9506}+\frac{1}{9630}\right)\)
\(=\frac{2016}{5}.\left(\frac{1}{1}+\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{97.98}+\frac{1}{98.99}\right)\)
\(=\frac{2016}{5}.\left(\frac{1}{1}+\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{97}-\frac{1}{98}+\frac{1}{98}-\frac{1}{99}\right)\)
\(=\frac{2016}{5}.\left(1+1-\frac{1}{99}\right)\)
\(=\frac{2016}{5}.\frac{197}{99}\)
\(=\frac{44128}{55}\)