Solve the following system of equations algebraically for all values of x, y, and z: i have what they solve down to, but i cant get the first step where you get rid of two variables to find the first answer.

6. sarah saved $12.75 every week for a number of weeks, w. she received an additional $25 during the last week in which she saved money. write and solve an equation to find the number of weeks, w, for which sarah had saved money if she has $114.25 now.