Answer:
Based on the solution that is being on Part A, the method used is substitution.
Explanation:
The two equations in Part A were:
x = the number of weeks
Equation 1: Lyle's savings = 100 + 20x
Equation 2: Shaun's savings = 500 + 10x
Since we wanted to know when Lyle's and Shaun's savings will be equal, we substituted "Lyle's savings" in the equation with 500 + 10x. It made equation 1 become 500 + 10x = 100 + 20x.
Or, we substituted "Shaun's savings" in the equation with 100 + 20x. It made equation 2 become 100 + 20x = 500 + 10x.
From this, we were able to calculate that at week 40, both Lyle and Shaun will have the same amount in their savings account.
[tex]\begin{gathered} 500+10x=100+20x \\ 500-100=20x-10x \\ 400=10x \\ \frac{400}{10}=\frac{10x}{10} \\ 40=x \end{gathered}[/tex]
