Question

Kylie starts with $145 in her piggy bank. Each month she adds $20.

Which recursive function rule models the total amount in Kylie’s piggy bank at the end of each month?

an=145+an−1 and a1=20

an=145⋅an−1 and a1=20

an=20⋅an−1 ​ and a1=145

an=20+an−1 ​ and a1=145

Answer 1

Kylie's first month collection, a1= $ 145

Second month collection , a2= $145+ 20

Third month collection, a3 = $145 +2*20

.

.

.

.

so for n months collection = an-1+20

We get an= 20 + an-1 and a1=145