Answer:
[tex]→ \: { \tt{f(x) = {x}^{2} - x }}[/tex]
• when f(x) is f(a-4), x is (a - 4):
[tex]→ \: { \tt{f(a - 4) = {(a - 4)}^{2} - a}}[/tex]
• Expand the bracket, from quadratic equation rules:
[tex]{ \boxed{ \bf{ {(a - b)}^{2} = {a}^{2} - 2ab + {b}^{2} }}}[/tex]
• therefore:
[tex]→ \: { \tt{f(a - 4) = ( {a}^{2} - 8a + 16) - a}} \\ \\ → \: { \boxed{ \tt{f(a - 4) = {a}^{2} - 9a + 16}}}[/tex]
Answer:
Step-by-step explanation:
'x' shows up 3 times in f(x) =x^2-x. To evaluate f(a - 4), replace each instance of 'x' with 'a - 4:'
f(a - 4) = (a - 4)^2 - (a - 4)
This result could be left as is, or it could be expanded:
f(a - 4) = a^2 - 8a + 16 - a + 4, or
f(a - 4) = a^2 - 9a + 20
