Question

quantos termos tem a PA (17,24,31,...,430)

Answer 1

a1=17    r= 7   an=430

an= a1+(n-1)r

430-17 = (n-1)r

413 = (n-1)7

413/7= n-1

n-1 =59

n= 59+1

n= 60  termos  ***********