Question

Помогите пожалуйста takushnir​

Answer 1

к³-r²к-rк²+r³=(r³+к³)-rк*(r+к)=(r+к)(r²-rк+к²)-(rк)(r+к)=(r+к)*(r²-2rк+к²)=

(r-к)²*(r+к)