Answer:
Step-by-step explanation:
Answer:
a) y-8 = (yâ‚€-8) Â , b) 2y -5 = (2yâ‚€-5)
Explanation:
To solve these equations the method of direct integration is the easiest.
a) the given equation is
      dy / dt = and -8
     dy / y-8 = dt
We change variables
      y-8 = u
     dy = du
We replace and integrate
      ∫ du / u = ∫ dt
      Ln (y-8) = t
We evaluate at the lower limits t = 0 for y = yâ‚€
      ln (y-8) - ln (y₀-8) = t-0
Let's simplify the equation
      ln (y-8 / y₀-8) = t
      y-8 / y₀-8 =
       y-8 = (y₀-8)
b) the equation is
       dy / dt = 2y -5
       u = 2y -5
       du = 2 dy
       du / 2u = dt
We integrate
       ½ Ln (2y-5) = t
We evaluate at the limits
       ½ [ln (2y-5) - ln (2y₀-5)] = t
       Ln (2y-5 / 2y₀-5) = 2t
       2y -5 = (2y₀-5)
c) the equation is very similar to the previous one
       u = 2y -10
       du = 2 dy
       ∫ du / 2u = dt
       ln (2y-10) = 2t
We evaluate
       ln (2y-10) –ln (2y₀-10) = 2t
        2y-10 = (2y₀-10)