I'll assume the question marks are due to some buggy code, and that the expression you're supposed to simplify is just
[tex]\dfrac{x^2+9x+20}{x+7}[/tex]
We carry out the division algorithm:
Since [tex]x^2=x\cdot x[/tex], we can multiply [tex]x+7[/tex] by [tex]x[/tex] to get [tex]x^2+7x[/tex]. Then subtracting this from [tex]x^2+9x+20[/tex] gives a remainder of
[tex](x^2+9x+20)-(x^2+7x)=2x+20[/tex]
Next, since [tex]2x=2\cdot x[/tex], we can multiply [tex]x+7[/tex] by [tex]2[/tex] to get [tex]2x+14[/tex], then subtracting this from the previous remainder gives a new remainder of
[tex](2x+20)-(2x+14)=6[/tex]
To summarize, we simplified the rational expression as
[tex]\dfrac{x^2+9x+20}{x+7}=x+\dfrac{2x+20}{x+7}=x+2+\dfrac6{x+7}[/tex]
so that the quotient terms is [tex]x+2[/tex], and the remainder is [tex]6[/tex].
