Question

Tina is saving to buy a notebook computer. She has two options. The first option is to put $400 away initially and save $10 every month. The second option is to put $300 away initially and save $30 every month. After how many months would Tina save the same amount using either option? How much would she save with either option?

Answer 1

After 5 months, both options will have saved 450$

Explanation:

The first option can be modeled with the expression

400 + 10x

The second option can be modeled with the expression

300 + 30x

The variable x represents the months so in order to find the month where Tina saves the same amount, we set the expressions equal to each other.

400 + 10x = 300 + 30x

solve for x

20x = 100

x = 5

After 5 months, Tina will save the same amount of money which is

400 + 10*5 = $450