Giải:
\(B=2010-1-2-3-4-...-99-100\)
\(B=2010-\left(1+2+3+4+...+100\right)\)
Đặt \(A=1+2+3+4+...+99+100\)
Số số hạng của \(A\)là: \(\left(100-1\right)\div1+1=100\)(số hạng)
Tổng \(A\)là: \(\left(100+1\right)\times100\div2=5050\)
Vậy \(B=2010-5050=-3040\)
(100-99+98+97+96-95+.....................+4-3+2-1)/50+2010-12*X=91
Tìm x :
( 100 - 99 + 98 - 97 + 96 - 95 + .......+ 4 - 3 + 2 - 1 ) : 50 + 2010 - 12 x X = 91
Cho A = 100+1/99+2/98+...99/1
B = 100-1/2-2/3-3/4-...-98/99
Tính A/B
Tính nhanh
a.(1+1/2)×(1+1/3)×(1+1/4)×...×(1+1/98)×(1+1/99).
b.1/2×2/3×3/4×...×97/98×98/99×99/100
tính nhanh (2/3+3/4+5/6+...+99/100).(1/2+2/3+3/4+...+98/99)-(1/2+1/3+...+99/100).(2/3+2/4+...+98/99)
Tính A:B
a)A=98+1/2+1/3+1/4+...+1/99
B=2/3+4/3+5/4+...+100/99
b)A=2018+1/2+1/3+1/4+...+1/2019
B=3/2+4/3+3/4+...+2020/2019
c)A=99/1+98/2+97/3+...+2/98+1/99
B=1/2+1/3+1/4+...+1/100
Giải đầy đủ
200 - 18 : (372:3.x-1)-28=166
(100-99+98-97+96-95+...+4-3+2-1):50+2010-12.x=91
x-(31/3+31/15+31/35+31/63+31/99+31/143)=9/13
1*2*3+2*3*4+3*4*5+....+97*98*99+98*99*100 = ?
A=101+100+99+98+...+3+2+1/101-100+99-98+...+3-2+1
B=3737.43/4343.37
