Equation

t + 7   
t2 - 8t + 16
  = - 4 +  
2t + 1   
t - 4

  The common denominator is (t - 4)(t - 4). Multiple both sides by (t - 4)(t - 4).

(t - 4)(t - 4) 
t + 7   
(t - 4)(t - 4)
  = - 4(t - 4)(t - 4) + (t - 4)(t - 4) 
2t + 1   
t - 4

t + 7 = -4(t - 4)(t - 4) + (t - 4)(2t + 1)

t + 7 = -4(t2 - 8t + 16) + (t - 4)(2t + 1)

t + 7 = -4t2 + 32t - 64 + 2t2 + t - 8t - 4

t + 7 = -2t2 + 25t - 68

2t2 - 25t + 68 + t + 7 = 0

2t2 - 24t + 75 = 0

t = (12 ± i√6)/2
return