I dont know how to do it

Answer:
[tex]8x^{2} +10x[/tex].
Step-by-step explanation:
Split them into sections.
The first one is [tex]x(2x+1)[/tex], which is [tex]2x^{2} +x[/tex].
The second one is [tex](2x+x)(2x+3)[/tex], which is [tex]6x^{2} +9x[/tex].
Add [tex]2x^{2} +x[/tex] and [tex]6x^{2} +9x[/tex], which is equal to [tex]8x^{2} +10x[/tex].
Hope I helped!