Alright to answer this question we have to set up an equation. For greg the equation is y=13x+26 and for lucy the equation is y=10x+35. y is total amount of money saved and x is number of weeks. Since we want them to each of the same amount of money we set up the equations to be 10x+35=13x+26
then we want to get the constant and the variables alone on different sides of the equal sign so we first subtract 26 from each side to get 10x+9=13x. next we want to subtract 10x from each side and then we end up with 3x=9. Finally we divide 3 from each side to get x=3, We have answered the question to how many week it will take them to save the same amount of money but not the other part. To find out how much money they will both have in 3 weeks we plug in 3 to x. 10(3)+35 which is equal to 65. They will both have 65 dollars in three weeks
