Question

Tina is saving to buy a notebook computer. She has two options. The first option is to put $200 away initially and save $10 every month. The second option is to put $100 away initially and save $30 every month. After how many months would Tina save the same amount using either options? How much would she save with either option?

Answer 1

Answer: In five months,she will save the same money which is $250.

Explanation:

Using the first statement we can generate the function y=10x + 200 and using the second statement we can also generate the function y = 30x + 100 . Now using the two equations solve for x and y to determine how many months they cost the same.

y = 10x + 200

y = 30x + 100

Substitute the value of x in the first equation into the second equation.

30x + 100= 10x + 200 now solve for x

-100 -100

30x = 10x + 100

-10x -10x

20x = 100

x= 5

This means in five months Tina will save the same amount. Now to find out how much the amount is, plot the value of x into one of the equations and solve for y.

y = 10(5) + 200

y = 50 + 200

y = 250

She will save $250 with either option.