Answer:
[tex]f=-18a^2+3[/tex]
Step-by-step explanation:
Given equation:
[tex]f=3-2(3a)^2[/tex]
[tex]\textsf{Apply exponent rule} \quad (ab)^n=a^n b^n:[/tex]
[tex]\implies f=3-2(3^2a^2)[/tex]
Rewrite 3² as 9:
[tex]\implies f=3-2(9a^2)[/tex]
Remove the parentheses:
[tex]\implies f=3-2 \cdot 9a^2[/tex]
Multiply the numbers 2 · 9 = 18 :
[tex]\implies f=3-18a^2[/tex]
Rearrange to make the variable the first term:
[tex]\implies f=-18a^2+3[/tex]
