60n/15^n-2*2^2n+1 упростите
60n/15^(n-2) x 2^(2n+1) = (4x15)^n/15^(n-2) x 2^(2n+1) = (2^2 x 15)^n/15^(n-2) x 2^(2n+1) = 2^2n x 15^n/15^(n-2) x 2^(2n+1) = 2^(2n+2n+1) x 15^(n-n+2) = 2^(5 n+1) x 15^2