mọi ng ơi lm nhanh giúp m nha

Đk x khác 0

pt 1.3+1/1.3 . 2.4+1/2.4 . ...... . x.(x+2)+1/x.(x+2) = 31/16

2^2/1.3 . 3^2/2.4 . ...... . (x+1)^2/x.(x+2) = 31/16

31/16 = 2^2.3^3. .... .(x+1)^2/1.3.2.4. .... .x.(x+2)

= 2.3. ..... .(x+1)/1.2. .... .x . 2.3. .... . (x+1)/3.4. .... .(x+2)

= (x+1).2/(x+2)

x+1/x+2 = 31/16 : 2 = 31/32 = 30+1/30+2

x = 30

Vậy ..............

Tk mk nha