Question

Calculati X si aratați ca este patratul unui numar natural,dupa care calculati radical din X:
x=3(1+3+5+...+99)-5000​

Answer 1

1+3+5+...+(2n-1)=n^2

2n-1=99

2n=99+1

2n=100

n=100/2

n=50=>n^2=50^2

x=3*50^2-5000

x=3*2500-5000

x=7500-5000

x=2500

x=50^2=>pătrat perfect

√x=√(50^2)=|50|=50

√a^2=|a|=a