Answer:
[tex]\left(7x+12\right)\left(7x-12\right)[/tex]
Step-by-step explanation:
apply the exponent rules: [tex]\left(7x\right)^2-12^2[/tex]
apply the difference of squares formula: [tex]\left(7x\right)^2-12^2=\left(7x+12\right)\left(7x-12\right)[/tex]
final answer: [tex]\left(7x+12\right)\left(7x-12\right)[/tex]