Please help me I’ll make u brainliest

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)