Factor completely each polynomial, and indicate any that are not factorable using integers. 4x2+16

Step 1
To factor completely each polynomial, and indicate any that are not factorable using integers.
${\displaystyle 4x^2+16}$
Step 2
Now, let us factor each term of the given polynomial,
${\displaystyle 4x^2+16}$
Consider,
${\displaystyle 4x^2=2\cdot 2\cdot x\cdot x}$
16=2*2*2*2
From, the above factored terms it is clear that the terms common are 2.2, so we can factor the polynomial,
${\displaystyle 4x^2+16=2\cdot 2(x\cdot x+2\cdot 2)=4(x^2+4)}$