Answer:
(x+2)(x-2)
Step-by-step explanation:
We have ,
[tex]\bf = 5x^2 -4(x^2+1)\\\\ \bf= 5x^2-4x^2-4 \\\\\bf= x^2 - 4 \\\\\bf =(x)^2-(2)^2 \qquad\bigg\lgroup \red{ \sf (a+b)(a-b)=a^2-b^2}\bigg\rgroup \\\\\boxed{\red{\bf=(x+2)(x-2)}}[/tex]