Answer:
[tex]3x+2y^2+2(x+y)+2y+1[/tex]
Step-by-step explanation:
1) Split the second term in [tex]2{(x+2y)}^{2}+3(x+2y)+1[/tex] into two terms.
1 - Multiply the coefficient of the first term by the constant term.
[tex]2\times1=2[/tex]
2 - Ask: Which two numbers add up to 3 and multiply to 2?
2 and 1.
3 - Split [tex]3x+2y[/tex] as the sum of [tex]2(x+y)[/tex] and [tex]x+2y[/tex].
[tex]2x+2y^2+2(x+y)+x+2y+1[/tex]
2) Collect like terms.
[tex](2x+x)+2y^2+2(x+y)+2y+1[/tex]
3) Simplify.
[tex]3x+2y^2+2(x+y)+2y+1[/tex]
Thank you,
Eddie