Step-by-step explanation: Using what is given she has 72$ and she needs 288 and if she makes 24$ per week we can write the equation 72 + 24x = 288 with x being the amount of weeks. Then we can subtract 72 on both sides leaving 24x = 216. Then we will have to divide 24 on both sides to get x by itself. 216/24 = 9 so it will take 9 weeks. You can check by putting this equation in a calculator since you can't type 72 + 24x = 288 you can use y = 72 + 24x - 288 since the other side will be zero look for when y is zero x = 9.
When it comes to investing, compound interest is better since it allows funds to grow at a faster rate than they would in an account with a simple interest rate.
