How do you factor the trinomial #c² -2cd -8d²#?

2 Answers
May 19, 2018

#(c-4d)(c+2d)#

Explanation:

#"the factors of - 8 which sum to - 2 are - 4 and + 2"#

#rArrc^2-2cd-8d^2=(c-4d)(c+2d)#

May 19, 2018

#(c+2d)(c-4d)#

Explanation:

#c^2-2cd-8d^2#

find two numbers that their product is -8 and their sum is -2

which they are -4 and +2

now because of c and d they both are squared

(c+2d)(c-4d)

to check your solution try to multiply them if your answer is correct you will get the original equation back

#c^2-4cd+2cd-8d^2#

#c^2-2cd-8d^2#