1+(-3)+5+(-7)+....+17+(-19)
=(1+5+9+...+17)+)(-3+-7+...+-19)
=45+55
=100
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Các câu hỏi tương tự
Thực hiên phép tính:
\(\frac{1}{5}.\frac{4\left(3+\frac{1}{3}-\frac{3}{7}-\frac{3}{53}\right)}{3+\frac{1}{3}-\frac{3}{37}-\frac{3}{53}}:\frac{4+\frac{4}{17}+\frac{4}{19}+\frac{4}{2003}}{5+\frac{5}{17}+\frac{5}{19}+\frac{5}{2003}}\)
Bài 1: Tìm x , biết:
1) x - 2 -6 12) 3 . | x - 1 | - 5 7
2) -5 . x - ( -3 ) 13 13) -12 . ( x - 5 ) + 7 . ( 3 - x ) 5
3) 15 - ( x - 7 ) -21 14) ( x - 2 ) . ( x + 4 ) 0
4) 3 .x + 17 2...
Đọc tiếp
Bài 1: Tìm x , biết:
1) x - 2 = -6 12) 3 . | x - 1 | - 5 = 7
2) -5 . x - ( -3 ) = 13 13) -12 . ( x - 5 ) + 7 . ( 3 - x ) = 5
3) 15 - ( x - 7 ) = -21 14) ( x - 2 ) . ( x + 4 ) = 0
4) 3 .x + 17 = 2 15) ( x - 2 ) . ( x + 15 ) = 0
5) 45 - ( x - 9 ) = -35 16) ( 7 - x ) . ( x + 19 ) = 0
6) ( -5 ) + x = 15 17) -5 < x < 1
7) 2 . x - ( -17 ) = 15 18) | x | < 3
8) | x - 2 | = 3 19) ( x - 3 ) . ( x - 5 ) < 0
9) | x - 3 | - 7 = 13 20) 2 . x2 - 3 = 29
10) 72 - 3 . | x + 1 | = 9 21) -6 . x - ( -7) = 25
11) 17 - ( 43 - | x | ) = 45 22) 46 =- ( x - 11 ) = -48
1) a) (-17)+5+8+17+(-3) b)25*2^2-(15-18)+(12-19+10
2) a) x+5=20-(12-7) b) 35-3gia tri tuyet doi cua x =5*(2^3-4)
Cho A=7^17+17*3-1 chia hết cho 9
Chứng tỏ B=7^18+19*3-1 chia hết cho 9
13) -12( x - 5 ) + 7( 3 - x ) = 5
14) ( x - 2 ) . ( x + 4 ) = 0
15) ( x - 2 ) . ( x + 15 ) = 0
16) ( 7 - x ) . ( x + 19 ) = 0
17 ) -5 < x < 1
18) \(\left|x\right|\) < 3
19) ( x - 3 ) ( x - 5 ) < 0
20) 2x2 - 3 = 29
1. Tính
a, 1+7+8+15+23+...+160
b, 17+4+5+9+19+...+60+9
c, 78*3+78*24+78*17*22*72
d, 53*39+47*39+47-53*21-47*21
e, 2*53*12+4*6*87-3*8*40
g, 5*7*77-7*60+49*25-15*42
h, 1*2+2*3+3*4+...+2016*2017
24 tháng 7 2017 lúc 9:36
tính
a,\((15.\dfrac{3}{5}-19\dfrac{7}{9})-(13\dfrac{3}{5}-17\dfrac{7}{9})\)
b,\([\dfrac{6}{5}-(\dfrac{3}{7}-2\dfrac{1}{7})\div\dfrac{4}{7}].(-\dfrac{3}{5})+\dfrac{2}{3}\div(-\dfrac{5}{6})\)
giúp mình nhé
-3+7+(-6)=
-4+(-3)+5=
-5+(-9)+8+(-3)=
7+(-8)+9+(-10)=
-5+12+(-4)=
|-14|+|-13|+(-17)+(-19)=
lam co tick
Tìm x
a / (6 frac{2}{7} .x + frac{3}{7} ): 2frac{1}{5} - frac{3}{7} -1
b/ 5 frac{8}{17} : x + (- frac{1}{17}): x + 3 frac{1}{17}: 17frac{1}{3} frac{4}{17}
c/ frac{1}{1.4}+frac{1}{4.7}+frac{7}{7.10}+ ...+ frac{1}{xleft(x+3right)} frac{6}{19}
Đọc tiếp
Tìm x
a / (6 \(\frac{2}{7}\) .x + \(\frac{3}{7}\) ): 2\(\frac{1}{5}\) - \(\frac{3}{7}\) = -1
b/ 5 \(\frac{8}{17}\) : x + (- \(\frac{1}{17}\)): x + 3 \(\frac{1}{17}\): 17\(\frac{1}{3}\)= \(\frac{4}{17}\)
c/ \(\frac{1}{1.4}\)+\(\frac{1}{4.7}\)+\(\frac{7}{7.10}\)+ ...+ \(\frac{1}{x\left(x+3\right)}\)= \(\frac{6}{19}\)