Dãy trên có ssh là:
(100-1):1+1=100 ( số hạng)
Ta có:
(x+1)+(x+2)+(x+3)+...+(x+100)=5070
=> 100x+(1+2+...+100)=5070
=> 100x + (100+1)x100:2=5070
=> 100x=20
=> x= 0.2
1.Tim x biet
a/5*x = 100
b/219-2*x = 77
c/18 * (x + 27) = 360
d/ ( 7 * x - 140 ) / 21 = 49
e/350 + 3 * x = 470
x*(3-x)=0
(x+2)*(4*x-8)=0
(x+1)+(x+2)+(x+3)+...+(x+100)=5750
tim x
tim x
( x +1) + (x +2) +(x+3)+ ..... + (x+99)+(x+100) = 5150
Tim x biet : ( x + 1 ) + ( x + 2 ) + ... + ( x + 100 ) = 5750
tim x biet
a] X+4x2=14,3x2 B] 8.75 x X +1,25 x X = 26,3 C] 1/5+[x-1]=0,2 D] 1/3+1/2 x X=1 E] [X-3/4 ] x 2+1/2-1,5 = 1 F] [X-5] x [3-x] = X-5
Thu gọn biểu thức:
A = 10 + 11 + 12 + ... + 100
B = 10 + 12 + ... + 200
C = 11 + 13 + ... + 99
D = 1 + 4 + 7 + ... + 100
E = 1 x 2 + 2 x 3 + ... + 49 x 50
F = 1 x 2 x 2 + 2 x 3 x 4 + ... + 48 x 49 x 50
tim x biet 3/5 - 1/4 : x = 25/100
tim x
100-(x:5+3/2)=80
tim x
100-(x:5+3/2)=80
