(x + 1) + (x + 4) + (x + 7) + ... + (x + 28) = 155
10x + (1 + 4 + 7 + ... + 28) = 155
10x + (28 + 1).[(28 - 1) : 3 + 1] : 2 = 155
10x + 29.10 : 2 = 155
10x + 29.5 = 155
10x + 145 = 155
10x = 155 - 145
10x = 10
x = 1
Tìm x , biết :
( x + 1 ) + ( x + 4 ) + ( x + 7 ) + ... + ( x + 28 ) = 155
TÌM X
(X+1)+(X+4)+(X+7)+(X+10)+....+(X+28)=155
tìm x:
(x+1) + (x+4) + (x+7) ....+ (x+28) = 155
(x +1) + (x+4) + (x+7) + ... .+ (x+28) =155. tìm x
Giusp tôi với:
Tìm x
(X +1 ) + ( x + 4 ) + ( x +7 ) +...... + ( x + 28 ) = 155
Tìm x
d)( x+1) +(x +4) +(x+7)+...+ (x+28)=155
e) (x+140): x + 260 =71+65x4
Tìm x :
( x + 1 ) + ( x + 4 ) + ( x + 7 ) + ...... + ( x + 28 ) = 155
giúp mk nhanh nha
(x +1)+ (x=4)+(x+7)+...+(x+28)=155
2. tìm x , biết:
a) 2x + 25 = 145
b) 216 : x +34 : x = 10
c) 2017 : x - 17 : x = 1000
d) 4057 + ( 2x : 38 ) =20395
e) ( x + 1 ) + ( x + 4 ) + ( x + 7 ) + ........ + ( x + 28 ) =155
