Gayle starts to save at age 20 for an extended vacation around the world that she will take on her 45th birthday. she will contribute $1000 each year to the account, which earns 1.65% annual interest, compounded quarterly. what is the future value of this investment when she takes her trip?

For this case we have the following equation:
 P (t) = P (1 + r / n) ^ (n * t)
 Where,
 P: initial investment
 r: interest
 n: periods
 t: time
 she will take on her 45th birthday:
 for t = 25:
 P (25) = 1000 * (1 + 0.0165 / 4) ^ (4 * 25)
 P (25) = 1509.31 $
 
 The future value of this investment when she takes her trip is:
 P (25) = 1509.31 $

Abit confused about what you mean, but i think you might be referring to slope intercept form: y = mx + bin that case b, or the y intercept is already given.(0,-1)find the slope by using the formulay2 - y1/x2 - x1the final slope will be 4/2, equivalent to 2.now your equation should look like thisy = 4/2x -1sorry if this didn’t you out!