find the values of a and b if s = -600 + 0.25y and c = a + by
solve both eqautions for y the only common factor.
s + 600 = .25y c - a = by
(s + 600)/.25 = y (c - a)/b = y
set the equations equal to each other y = y
(s + 600) / .25 = (c - a) /b
1). now solve for the value b
multiply by .25b
(s + 600)b = .25(c - a)
b = [.25(c - a)]/(s + 600)
2). (s + 600) / .25 = (c - a) /b now solve for a
multiply by b
[b(s + 600)/.25] = c - a
{[b(s + 600)/.25] - c} = - a
{-b[(s + 600)/,25] - c} = a