Answer:
Hello!!! Princess Sakura here ^^
Step-by-step explanation:
For the f(-2):
[tex]f(-2)=8(-2)-4\\f(-2)=-16-4\\f(-2)=-20[/tex]
For the f(x+7):
[tex]f(x+7)=8(x+7)-4\\f(x+7)=8x+56-4\\f(x+7)=8x+52[/tex]
For the f(-x):
[tex]f(-x)=8(-x)-4\\f(-x)=-8x-4[/tex]
That's all