Question

Tìm x:

(x+2)+(x+4)+(x+6).........+(x+50)=750

Answer 1

\(\left(x+2\right)+\left(x+\text{4 }\right)+\left(x+6\right)+...+\left(x+50\right)=750\)

\(x+2+x+4+x+6+...+x+50\) =750

(x+x+x...+x)+(2+4+6+..+50) =750

25x+650 =750

25x =750-650

25x =100

x =100:25

x =4

Answer 2

(x + 2) + (x + 4) + (x + 6) + ... + (x + 50) = 750

\(\Rightarrow\) (x + 2 + x + 50) . 25 : 2 = 750

\(\Rightarrow\) (x . 2 + 52) . 25 = 1500

\(\Rightarrow\) x . 2 + 52 = 60

\(\Rightarrow\) x . 2 = 8

\(\Rightarrow\) x = 4