Question

16)Quantos termos tem a P.A(17,26,,35.....197? kero cálculo bb

Answer 1

r = a2 - a1r = 26 - 17r = 9
an = a1 + (n - 1).r197 = 17 + (n - 1).9197 = 17 + 9n - 9197 = 8 + 9n189 = 9n189/9 = n21 = n

Answer 2

An=a1(n-1)r
197=17(n-1)9
197=17+9n-9
197=8+9n
197-8=9n
189=9n
n=189/9
n=21 termos