Question

x la a 2 a +25= 2+4+6+...+50 ;
x=?
Sunt a 7-a doar ca nu am mai facut de mult timp tipul asta de ex. asa ca am uitat cum se rezolva .. URGENT!!

Answer 1

x²+25=(2+50)•25/2
x²+25=52•25/2
x²+25=26•25
x²=26•25-25
x²=25(26-1)
x²=25•25
x²=25²
x=25

Answer 2

x²+25=(2+50)×25/2
x²+25=52×25/2
x²+25=26×25
x²=26×25-25
x²=25(26-1)
x²=25×25
x²=25²
x=25

Sper că te-am ajutat!