Question

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

Answer 1

anyy help

Answer 2

@welshfella

Answer 3

@Vocaloid

Answer 4

@Vocaloid i am your 200th fan the least u could do is help me out

Answer 5

a(x) = 3x - 12
a((b(x)) = 3*b(x) - 12 = 3(x-9) - 12

Answer 6

what do i do

Answer 7

a(x) = 3x - 12, right?

a(b(x)) means replace "x" with b(x), so

a(b(x)) = 3*b(x) - 12

now, we know that b(x) = x - 9, so we can replace "b(x)" with (x-9), giving us

a(b(x)) = 3(x-9)-12
distribute the 3 and simplify

Answer 8

3x-39 ?? @Vocaloid

Answer 9

yes