K $>$ L $>$ M $>$ N are positive integers such that$,$ KM $+$ LN $=$ (K$+$L$-$M$+$N)($-$K$+$L$+$M$+$N)$.$ Prove that KL $+$ MN is not prime.
I'm stumped :/
K $>$ L $>$ M $>$ N are positive integers such that$,$ KM $+$ LN $=$ (K$+$L$-$M$+$N)($-$K$+$L$+$M$+$N)$.$ Prove that KL $+$ MN is not prime.
I'm stumped :/