I have a formula as follows:
y = a*(x-x4) + b*(x-x4-x3) + c*(x-x4-x3-x2) + d*(x-x4-x3-x2-x1)
Knowing that y, x1, x2, x3, x4 are always greater than 0.
y is less than 86400
x1 + x2 + x3 + x4 is always less than 86400
x1 + x2 + x3 + x4 = x
knowing that x is less than 86400
and x4 > x3 > x2 > x1 > 0
0 <a < b < c < d

The formula has the following results for x, y in each experiment:

x = 560, y = 460
x = 2260, y = 1260
x = 1200, y = 1020
x = 7320, y = 6000
x = 8880, y = 7320
x = 36900, y = 21600
x = 18180, y = 9300
x = 25260, y = 16920

I don't want to calculate the specific values, but please provide approximate values for x1, x2, x3, x4, and a, b, c, d so that the equation has y close to x. There should be exactly 3 paragraphs separated by the markdown divider: ***.
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