Question

Rezolvați ecuația x+2x+3x+...+100x=50500

Answer 1

factor comun x
x(1+2+....100)=50500
$S100= \frac{(a1+an)n}{2}= \frac{(1+100)100}{2} =5050$
5050x=50500
x=10

Answer 2

(1+2+3+...+100)*x=50500
($\frac{100*101}{2}$)*x=50500
5050*x=50500
x=$\frac{50500}{5050}$
x=10