# Amazing equations!!!

**Algebra**Level pending

Consider equations

(x-y)(x+2y)(2x+y)=160
AND
x^2 + xy + y^2 = 28
AND
(x-y)(x+2y)=k

Find the values of k (-21<k<21) such that all three equations meet simultaneously at a point.
If the possible values of k are k1 and k2 then find
|k1|+|k2| ...............that is sum of absolute value.
PLEASE DONT GUESS OR USE INTERNET.. AND post your solution