Question

quantos termo a P.A (17,26,35....197}?

Answer 1

An= 197
a1= 17
n=?
r=9

an= a1+(n-1)r
197= 17+(n-1)9
197-17=9n-9
180+9=9n
189=9n
189/9=n
21=n

Answer 2

A1 = 17
AN =197
R = 26 -17 = 9
N=?
AN = A1 + (N-1) * R >>> 197 = 17 + (N-1) * 9
197 - 17 = 9N -9 >>>> 180 = 9N - 9 >>> 180 + 9 = 9N > 189 = 9 N
N= 189/9  >>> N= 21.
LOGO TEMOS 21 TERMOS.