stalMcarc8Te1sher stalMcarc8Te1sher 19-05-2016 Mathematics contestada 1. Given the functions a(x) = 3x − 12 and b(x) = x − 9, solve a[b(x)] and select the correct answer below. a[b(x)] = 3x2 − 21 a[b(x)] = 3x2 − 39 a[b(x)] = 3x − 21 a[b(x)] = 3x − 39