Question

Rezolvati:

( x+1)+(x+2)+(x+3)+...+(x+50)=2275

Answer 1

x+....+x (de 50 ori+1+2+3+.....+50=2275

adica 50*x+(1+2+3+....+50)=2275

aplicam suma gauss si 1+2+3+...+50=50*(50+1):2=50*51:2=25*51=1275

deci 50*x+1275=2275, 50*x=2275-1275=1000, X=1000:50=20