Question

Example four

Lyle and Shaun open savings accounts at the same time. Lyle deposits $100 initially and adds $20 per week. Shaun deposits $500 initially and adds $10 per week. Lyle wants to know when he will have the same amount in his savings account as Shaun.
Part A: Write two equations to represent the amounts of money Lyle and Shaun have in their accounts
f(x)=
g(x)=
Part B: to solve the system you will make f(x)=g(x)

Answer 1

100 + (20 × w), 500 + (10 × w), w = 40

Explanation:

The equations you can use for Lyle and Shaun's can look something like this:

amount initially deposited + (amount deposited every week × amount of weeks) = total amount of cash in account.

Now all we need to do is use this equation to solve for Lyle and Shaun.

(weeks = w)

Lyle's account can look something like this:
100 + (20 × w) = amount of cash

Shaun's account can look something like this:
500 + (10 × w) = amount of cash

Now all we need to do is figure out the value of w.

If w was equal to 20, the equations would look like this:

Lyle's equation:

100 + (20 × 20) = 500

Shaun's equation:

500 + (10 × 20) = 700

As you can see, the equations don't line up just yet. Let's try 40.

Lyle's equation:
100 + (20 × 40) = 900

Shaun's equation:

500 + (10 × 40) = 900

Now, the equations line up!

So, this means that w = 40.