(x + 1) + (x + 3) + (x + 5) + (x + 7) + (x + 9) = 130
=> x + 1 + x + 3 + x + 5 + x + 7 + x + 9 = 130
=> (x + x + x + x + x) + (1 + 3 + 5 + 7 + 9) = 130
=> 5x + \(\frac{\left(1+9\right)\cdot5}{2}\)= 130
=> 5x + 25 = 130
=> 5x = 105
=> x = 105 : 5 = 21
( x + 1 ) + ( x + 3 ) + ( x + 5 ) + ( x + 7 ) + ( x + 9 ) = 130
x + 1 + x + 3 + x + 5 + x + 7 + x + 9 = 130
5x + 25 = 130
5x = 130 - 125
5x = 105
x = 21
(x+1)+(x+3)+(x+5)+(x+7)+(x+9)=130
(x+x+x+x+x)+(1+3+5+7+9)=130
5x+25=130
5x=130-25
5x=105
x=105:5
x=21
Hok tốt !!!!!!!!!!!!!!!!!!!!!
\(\left(x+1\right)+\left(x+3\right)+\left(x+5\right)+\left(x+7\right)+\left(x+9\right)=130\)
\(x+1+x+3+x+5+x+7+x+9=130\)
\(\left(x+x+x+x+x+x\right)+\left(1+3+5+7+9\right)=130\)
\(5x+\frac{\left(1+9\right)\cdot5}{2}=130\)
\(5x+25=130\)
\(5x=105\)
\(x=21\)
(X+1) + (X+3) + (X+5) + (X+7) + (X+9) = 130
<=> X+1 + X+3 + X+5 + X+7 + X+9 = 130
<=> 5x + ( 1 + 3 + 5 + 7 + 9 ) = 130
<=> 5x + ( 9 + 1 x ( 9 - 1 : 2 + 1 ) : 2 ) = 130
<=> 5x + ( 10 x 5 : 2 ) = 130
<=> 5x + 25 = 130
<=> 5x = 130 - 25
<=> 5x = 105
=> x = 105 : 5
=> x = 21
Hok tốt
\(\left(x+1\right)+\left(x+3\right)+\left(x+5\right)+\left(x+7\right)+\left(x+9\right)=130\)
\(\Rightarrow x+1+x+3+x+5+x+7+x+9=130\)
\(\Rightarrow x.5+\left(1+3+5+7+9\right)=130\)
\(\Rightarrow x.5+25=130\)
\(\Rightarrow x.5=130-25\)
\(\Rightarrow x.5=105\)
\(\Rightarrow x=105:5\)
\(\Rightarrow x=21\)
Vậy x=21
