a) n/16 = 3/4 => 4n = 16 * 3 => 4n = 48 => n = 12
b) (n+1)/8 = 3/4 => 4n + 4 = 24 => 4n = 20 => n = 5
c) 6/(n-1) = 3/4 => 24 = 3n - 3 => 3n = 27 => n = 9
d) 30/2n = 3/4 => 120 = 6n => n = 120/6 => n = 20
e) 3/(7n-10) = 3/4 => 12 = 21n - 30 => 21n = 42 => n = 2
f) 12/(3n+4) = 3/4 => 48 = 9n + 12=> 9n = 36 => n = 4
g) (n+2)/(n+3) = 3/4 => 4n + 8 = 3n + 9 => n = 1
h) 60/(n+7) = 3/4 => 240 = 3n + 21 => 3n = 219 => n = 73