factor
in form
ax²+bx+c form
use the ac method
1. mulitply a and c
2. factor the result such that the 2 factors add to b
3. split b into those 2 factors
4. group the terms
5. undistribute common factors
6. undistribute again
first multiply ac
4 times 5=20
now
what 2 numbers multiply to 20 and add to 12
2 and 10
4x²+2x+10x+5
group
(4x²+2x)+(10x+5)
undistribute
2x(2x+1)+5(2x+1)
undistribute the (2x+1)
(2x+1)(2x+5) is factored form whih you have there, nice