How do you factor the trinomial #12k^2+15k=16k+20#?

1 Answer
Nov 18, 2015

The factors are: #(3k - 4)(4k+ 5)#

Explanation:

#12k^2-k-20=0#
Integer factors of 12 are: {1,12} , {2,6}, {3,4}

Integer factors of 20 are: {1,20}, {2,10}, {4,5}

The combination that could yield #12k^2# and #k# are
{3,4} for 12 and {4,5} for 20

Try-1
#(3k - 4)(4k+ 5) =12k^2 +15k -16k -20#

#color(green)("Struck lucky first try!")#

#12k^2+15k=16k+20 color(white)(xx) -> color(white)(xx)(3k - 4)(4k+ 5)=0#