Question

determine o numero de
termos da pa 2,10,18....250

Answer 1

an = a1 + ( n-1 ) .r
250 = 2 + (n-1) 8
250 = 2 + 8n - 8
250 = 8n - 6
250 + 6 = 8n
8n = 256
n = 256/8
n = 32             ok

Answer 2

an= a1+ (n-1) . r          an=250
250= 2 +( n-1). 8        a1=2
250-2= 8n -8                r=8      essa P.A possui 32termos
248+8=8n
256=8n
256/8=n
32=n