Factoring quadratic trinomials when a=1

 $Factor\ \ x^2+5x+6$  

• (x+5)(x+1)

• (x+6)(x+1)

• (x+6)(x-1)

• (x+2)(x+3)

 $Factor\ \ \ \ \ x^2-8x+15$  

• (x+5)(x+3)

• (x-4)(x-2)

• (x-5)(x-3)

• (x+5)(x-3)

 $Factor\ \ \ \ x^2+6x-40$  

• (x-4)(x+10)

• (x-4)(x-10)

• (x-8)(x+5)

• (x-5)(x+8)

 $Factor\ \ \ \ x^2-x-12$  

• (x-4)(x-3)

• (x-6)(x+2)

• (x-6)(x-2)

• (x-4)(x+3)

 $Factor\ \ \ \ x^2-12x+27$  

• (x-27)(x-1)

• (x-4)(x+3)

• (x-9)(x-3)

• (x+9)(x+3)