Question

Determine a soma dos trinta primeiros números naturais impares

Answer 1

1+3+5+7+9+11+13+15+17+19+21+23+27+29+31+33+35+37+39+41+43+45+47+49+51+53+55+57+59+61=936

Answer 2

resolução!

an = a1 + ( n - 1 ) r

an = 1 + ( 30 - 1 ) 2

an = 1 + 29 * 2

an = 1 + 58

an = 59

Sn = ( a1 + an ) n / 2

Sn = ( 1 + 59 ) 30 / 2

Sn = 60 * 15

Sn = 900