Question

If limxtends to 2 xn-2n /x-2=80 what is n

Answer 1

lim x-->2 (x^n - 2n )/ (x-2) = 80

  by using L-Hospital rule, the simplest one

 lim x-->2 {nx^(n-1)} = 80

   n (2)^n-1 = 80 = 5(2)^4 = 5(2)^5-1

    so, n=5