P=1+(-3)+5+(-7)+...17+(-19)
P=(-2)+(-2)+...+(-2)
P=(-2). 9,5 ( vì có 9,5 số -2)
P= -19
P=1+(-3)+5+(-7)+...17+(-19)
P=(-2)+(-2)+...+(-2)
P=(-2). 9,5 ( vì có 9,5 số -2)
P= -19
Cho phân số A=1+3+5+...........+19/21+23+25+..........+39
a}Rut gon A
Giup minh voi!
Rut gon roi quy dong mau cac phan so sau:
3 . 4 + 3 . 7/6 .5 + 9 va 6 . 9 - 2 . 17/63. 3 - 119
\(c=\frac{3}{1^2.x^2}+\frac{5}{^{2^2.3^2}}\)+\(\frac{7}{3^2.4^2}+...+\frac{19}{9^2.10^2}\).Rut gon C
rut gon
1+3+5+.....+19
21+23+25+....+39 p/s
Rut Gon B=\(\frac{5^{13}\cdot7^{18}+5^{14}\cdot7^{17}}{5^{13}\cdot7^{17}}\)
C= 3 / 1 x 1 x 2 x1 + 5 / 2 x2 x 3x2 +...+19 / 9 x9 x 10 x10 . Rut gon C
1,. Tính
A=10101*(5/111111+5/222222+4/3*7*11*13*37
2, Rut gon phan so
A. 6*9-2*17/63*3-119
B. 2*3+4*6+14*21/3*5+6*10+21*35
rut gon A=1+1^ 2+1^ 3+1^4+1^5+1^6+1^7+1^8+1^9+...+1^2012
rut gon 1+7^2+7^3+7^4+...+7^99