Step-by-step explanation:
[tex]3(4 {x}^{2} + 9) - 1[/tex]
[tex]12 {x}^{2} + 27 - 1[/tex]
[tex]12 {x}^{2} + 26[/tex]
[tex]f(x) = 3x-1\\\\g(x) = 4x^2 +9 \\\\g(3) = 4\cdot 3^2 +9 = 36+9 =45\\\\(f\circ g)(3)\\\\=f(g(3))\\\\=f(45)\\\\=3(45)-1\\\\=134[/tex]
