For a polynomial of the form ax^2+bx+c rewrite the middle term as a sum of two terms whose product is a⋅c=5⋅4=20 and whose sum is b=12.
Factor 12 out of 12x.
5x^2+12(x)+4
Rewrite 12 as 2 plus 10
5x^2+(2+10)x+4
Apply the distributive property.
5x^2+2x+10x+4
Factor out the greatest common factor from each group.
Group the first two terms and the last two terms.
(5x^2+2x)+10x+4
Factor out the greatest common factor (GCF) from each group.
x(5x+2)+2(5x+2)
Factor the polynomial by factoring out the greatest common factor, 5x+25x+2.
(5x+2)(x+2)