Answer:
[tex](f-g)(x) = -12x^{2} - 8x + 9[/tex]
(f-g)(-4) = -151
Step-by-step explanation:
To find f-g(x) we subtract the common terms. So
[tex]f(x) = -9x^{2} - 2x[/tex]
[tex]g(x) = 3x^{2} + 6x - 9[/tex]
(f-g)(x)
[tex](f-g)(x) = f(x) - g(x) = -9x^{2} - 2x - (3x^{2} + 6x - 9) = -9x^{2} - 2x - 3x^{2} - 6x + 9 = (-9 - 3)x^{2} + (-2 - 6)x + 9 = -12x^{2} - 8x + 9[/tex]
(f-g)(-4)
[tex](f-g)(x) = -12x^{2} - 8x + 9[/tex]
We replace x by -4
[tex](f-g)(-4) = -12(-4)^{2} - 8(4) + 9= -151[/tex]
(f-g)(-4) = -151
