Question

Tina is saving to buy a notebook computer. She has two options. The first option is to put S200 away initially and save $10 every month. The second option is to put s100 away initially and save s30 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

The equation for the first option is Y=10x + 200
The equation for the second option is Y=30x + 100

X = one month
To find when they would be the same about you have to set the equations equal to each other

10x + 200 = 30x + 100
-10x -100 -10x -100

100= 20x

5 = x

After five months she would save the same amount. To find how much is saved you have to plug in 5 for x in one of the equations. You can always double-check 5 by plugging it in both equations and making sure you get the same answer

Y= 10(5) + 200 = 250

Y= 30(5) + 100 = 250

She would have saved $250 after five months by using either method