Answer:
A₁ = $150.
Step-by-step explanation:
We know that:
Sarah has saved $150 at the moment.
She wants to double the amount that she saves each month, so the next month she needs to save 2*$150 = $300
And if she saves the $300, then her grandma will give her another $50.
Then, if the previous month Sarah saved A, then the next month she will get the double of A plus $50, which is:
2*A + $50
Then the recursive relation is just:
Where Aₙ is the amount that she saves in the n-th month, and the first term of the sequence is the initial amount that she saved, so we have:
A₁ = $150.
