suy ra x+x+x+....+x -(1+2+3+....+100)=4950
suy ra 100x -(100+1).100:2=4950
suy ra 100x - 101.100:2 = 4950
suy ra 100x - 5050 =4950
suy ra 100x = 4950 + 5050
suy ra 100x =10000
suy ra x=10000 : 100
suy ra x=100
(x-1)+(x-2)+(x-3)+...+(x-100)=4950. Tìm x
Tìm x, biết: (x - 1) + (x - 2) + (x - 3) + ...+ (x - 100) = 4950
tìm x :(x-1)+(x-2)+...............+(x-100)=4950
1 . A = 1 x 4 + 2 x 5 + 3x 6 + .... + 99 x 102
2 . A = 1 + 3 + 6 + 10 + ... + 4851 + 4950
3 . A = 6 + 16 + 30 + 48 + ... + 19600 + 19998
4 . A = 2 + 5 + 9 + 14 + ... + 4949 + 5049
5 . A = 22 + 42 + 62 + ... + 982 + 1002
6 . A = 1 x3 + 3 x 5 + 5 x 7 + .... + 97 x 99 + 99 x 101
7 . A = 12 + 32 + 52 + ... + 972 + 992
8 . A = 13 + 23 + 33 + ... + 993 + 1003
Giair hộ mik nhé !
Bài 2: Tìm x, biết:
a, | x+3 | = -27/11 × 22/-9
b, (x-3) × (2x - 7) = 0
c, (x-1) + (x-2) + (x-3) + ... + (x-100) = 4950
tìm x :(x-1)+(x-2)+...............+(x-100)=4950
1 x 100 + 2 x 99 + 3 x 98 + .....+ 99 x 2 + 100 x 1 = ?
Bài1:Thực hiện phép tính(tính nhanh nếu có thể)
A=21.72-11.72+90.72+49.125.16
\(B=\frac{2}{15}+\frac{2}{35}+\frac{2}{63}+\frac{2}{99}+...+\frac{2}{899}\)
C=1.2+2.3+3.4+......+99.100
Bài2:Tìmx, biết:
a)\(|x+3|=\frac{-27}{11}.\frac{22}{-9}\)
b)(x-3).(2x-7)=0
c)(x-1)+(x-2)+(x-3)+.......+(x-100)=4950
tìm x thuộc Z
a)1+2+3+.........+x=5050
b)1/2+1/6+........1x2+x=99/100
c)1/6+1/12+.......1/x2-x=59/100
d)x-2017+x-2016+.........+99+100=0
g)x-1+x-2+x-3+.......x-2017=0
