1) Ta có : x + (x + 1) + (x + 2) + ... + (x + 100) = 5555 (100 cặp)
=> x + x + 1 + x + 2 + .... x + 100 = 5555
=> (x + x + x + ... + x) + (1 + 2 + ... + 100) = 5555
100 số hạng 100 số hạng
=> 100x + 100.(100 + 1) : 2 = 5555
=> 100x + 5050 = 5555
=> 100x = 505
=> x = 5,05
Vậy x = 5,05
2) x + 2x + 3x + ... + 100x = 15150
=> x(1 + 2 + 3 + ... + 100) = 15150
=> x.(100.101 : 2) = 15150
=> x.5050 = 15150
=> x = 3
Vậy x = 3
Tìm số tự nhiên x,y biết:
a, x+2x+3x+...+100x = 15150
b, 2x +80 = 3y
1/Tìm x,biết:
a)x+(x+1)+(x+2)+(x+3)+...+(x+99)+(x+100)=5555
b)1+2+3+4+...+x=820
c)3(x+1)=9.27
d)x+2x+3x+...+99x+100x=15150
e)(x+1)+(x+2)+(x+3)+...+(x+100)=205550
f)3x+3x+1+3x+2=351
BÀI 1:Tìm x biết
a :3x -5 =x
b: 1.2.3.4.5......(x+1)=0
c:x+ 2x +3x +4x +5x+..............+100x=0
d:x +2x+3x+4x+5x+..................+100x=5050
e:(x+1)+(x+2) +(x+3) +(x+4)+............+(x+100)= 5050
Tìm số nguyên tố x,y:
a) x + 2x + 3x + ...... + 100x =15150
b) 2x + 80 = 3y
c) x + (x+1) = 2 + 4 + 6 + ... + 2500
d) 23 . x + 20100 . x = 995 - 15 : 3
e) ( x + 172 ) - 1 = 99
Bài 1 : Tính
a) B= 1002 + 2002+3002+...+10002
b) A=(49.36+644):(164.100) [phân số]
Bài 2 Tìm số nguyên tố x,y
a)x+2x+3x+4x+......+100x=15150
b)2x+80=3y
c)x.(x+1)= 2+4+6+...+2500
d)23.x+20100.x=995-15:3
e) (x+172) -1=99
chỉ giúp mình . ghi rõ nha
a). x+2x+3x+......+20x=2100
b). x+( x+1)+(x+2)+....+(x+100)=100x+600
c). (x-3) * (x-2)=0
d). x*2x-6x=0
Tìm x
a.2x+(1+2+3+4+...+100) = 15150
b.(x+1)+(x+2)+(x+3)+(x+4)+(x+5)+(x+6)+(x+7)+(x+8)=36
c.0+0+4+6+8+...+2x=110
(x+1)+(x+2)+(x+3)+...+(x+100)=15150
X+2.x+3:x+...+100.x=15150
