Question

Porfa ayuda
Calcula la suma de los 40 primeros múltiplos de 4 mayores que uno.
a) 1600
b)3280
c)4260
d)3060
e)1872

Answer 1

4; 8, 12, 16, 20 ....  t₄₀

$T_{n} = T_{1} + (n-1)r\\ \\T_{n} = 4 + (40-1)4\\\\T_{n} = 4 + (39)4\\\\T_{n} = 4 + 156\\\\T_{n} = 160$

$S = (\frac{T_{n} + T_{1} }{2} )n\\\\S = (\frac{160 + 4 }{2} )40\\\\S = (\frac{164}{2} )40\\\\S = (82 )40\\\\S = 3280$

Eternamente axllxa