Question

Calcule o valor da seguinte soma (2 + 3 + 4 ...+ 99 +100 +101): a)5050 b)5051c)5049d)5055e)N.D.A

Answer 1

r = a₂ - a₁
r = 3 - 2
r = 1

$A_{n} = a_{1} + (n -1) . r$
101 - 2 = (n -1) . 1
99 + 1 = n
100 = n

$S_{n} = \frac{ ( a_{1} + a_{n} ) . n}{2}$
s100 = (2 + 101) . 100/2
s100 = 103 . 50
s100 = 5150

e)N.D.A