How do you factor completely #2a^2 - 4a - 2#?
1 Answer
Oct 28, 2016
Explanation:
The difference of squares identity can be written:
#A^2-B^2 = (A-B)(A+B)#
Use this with
#2a^2-4a-2 = 2(a^2-2a-2)#
#color(white)(2a^2-4a-2) = 2(a^2-2a+1-3)#
#color(white)(2a^2-4a-2) = 2((a-1)^2-(sqrt(3))^2)#
#color(white)(2a^2-4a-2) = 2((a-1)-sqrt(3))((a-1)+sqrt(3))#
#color(white)(2a^2-4a-2) = 2(a-1-sqrt(3))(a-1+sqrt(3))#