\(\left(2x+1\right)+\left(4x+2\right)+....+\left(20x+10\right)=275\)
\(\Rightarrow\left(2x+4x+....+20x\right)+\left(1+2+3+....+10\right)=275\)
\(\Rightarrow110x+55=275\)
\(\Rightarrow110x=275-55\)
\(\Rightarrow110x=220\)
\(\Rightarrow x=2\)
(2x + 1) + (4x + 2) + (6x + 3) + ... + (20x + 10) = 275
(1 + 2 + 3 + ... + 10).(2x + 1) = 275
(1 + 10).10:2.(2x + 1) = 275
11.5.(2x + 1) = 275
55.(2x + 1) = 275
2x + 1 = 275 : 55
2x + 1 = 5
2x = 5 - 1
2x = 4
x = 4 : 2
x = 2
Vậy x = 2
(2x+1)+(4x+2)+(6x+3)+...+(20x+10)=275
<=>(2x+4x+6x+...+20x)+(1+2+3+...+10)=275
<=>110x+[(10+1).10:2]=275
<=>110x+55=275
=>110x=275-55
=>110x=220
=>x=220:110
=>x=2
Chúc bạn học giỏi nha!!!
K cho mik với nhé trần hiền anh
( 2x + 1 ) + ( 4x + 2 ) + ( 6x + 3 ) + ... + ( 20x + 10 ) = 275
=> ( 1 + 2 + 3 + ... + 10 ) . ( 2x + 1 ) = 275
=> ( 1 + 10 ) . 10 : 2 . ( 2x + 1 ) = 275
=> 11 . 5 . ( 2x + 1 ) = 275
=> 55 . ( 2x + 1 ) = 275
=> 2x + 1 = 275 : 55
=> 2x + 1 = 5
=> 2x = 5 - 1
=> 2x = 4
=> x = 4 : 2
=> x = 2
Vậy x = 2
( 2x + 1 ) + ( 4x + 2 ) + ( 6x + 3 ) + ... + ( 20x + 10 ) = 275
=> ( 1 + 2 + 3 + ... + 10 ) . ( 2x + 1 ) = 275
=> ( 1 + 10 ) . 10 : 2 . ( 2x + 1 ) = 275
=> 11 . 5 . ( 2x + 1 ) = 275
=> 55 . ( 2x + 1 ) = 275
=> 2x + 1 = 275 : 55
=> 2x + 1 = 5
=> 2x = 5 - 1
=> 2x = 4
=> x = 4 : 2
=> x = 2
Vậy x = 2
(2x + 1) + (4x + 2) + (6x + 3) + ... + (20x + 10) = 275
(1 + 2 + 3 + ... + 10).(2x + 1) = 275
(1 + 10).10:2.(2x + 1) = 275
11.5.(2x + 1) = 275
55.(2x + 1) = 275
2x + 1 = 275 : 55
2x + 1 = 5
2x = 5 - 1
2x = 4
x = 4 : 2
x = 2
Vậy x = 2
