In this case the answer is very simple . .
We must apply the distributive property of multiplication.
[tex](d^2+3)\cdot(d^2\text{ + 2d + 1) }[/tex][tex]d^2\cdot d^2+d^2(2d^{})+d^2+3(d^2\text{) + 3(2d) + 3}[/tex][tex]d^4\text{ + }2d^3+d^2+3d^2+6d+3[/tex][tex]d^4+2d^3+4d^2+6d+3^{}[/tex]That is the solution. .
