Question

Determinati numerele naturale care au patratul egal cu numarul a) n=13+2x(1+2+...+12) b) n=1003+ 2 x(1+2...1002)

Answer 1

a)13+2(1+2+3+...+12)=13+2*12*13:2=13+12*13=13(1+12)=13*13=169
b)1003+2(1+2+3+...+1002)=1003+2*1002*1003:2=1003+1002*1003=1003(1+1002)=1003*1003