Question

X2 + 8 x+ 12
X2+17x+72

Answer 1

so the like terms first .. if its x square then
x^2 (its x square ok?)
x^2 + x^2 + 8x + 17x +72 + 12
=2x^2 + 25x + 84

Answer 2

x2 + 8x + 12  
      x2 + 6x + 8x + 12 
     ( x2 +6x ) ( 8x + 12 )
     x( x + 6 ) + 2( x+ 6 )
        ( x + 2 ) ( x + 6 ) 
x2 + 17x + 72 
= x2 + 8x + 9x + 72 
= ( x2 + 8x ) ( 9x + 72 )
= x( x + 8 ) + 9( x+ 8 ) 
= ( x+ 9 ) ( x+ 8 )  
hope u have understand it