Let f(x) = x2 − 4 and g(x) = 4x − 3, how do you find (f − g)(−6)?

Mar 31, 2018

$59$

Explanation:

$\left(f - g\right) \left(x\right) = f \left(x\right) - g \left(x\right)$. so $\left(f - g\right) \left(x\right) = {x}^{2} - 4 x - 1$. Plugging in -6, you get that the answer is $59$

Mar 31, 2018

$\left(f - g\right) \left(- 6\right) = 59$

Explanation:

$\left(f - g\right) \left(- 6\right)$ = $f \left(- 6\right) - g \left(- 6\right)$

$f \left(- 6\right) = {\left(- 6\right)}^{2} - 4$
$f \left(- 6\right) = 36 - 4$
$f \left(- 6\right) = 32$

$g \left(- 6\right) = 4 \left(- 6\right) - 3$
$g \left(- 6\right) = - 24 - 3$
$g \left(- 6\right) = - 27$

$f \left(- 6\right) - g \left(- 6\right)$
$32 - \left(- 27\right)$
$32 + 27$
$59$