Answer:
Rewrite as
3x(x-y) -p[-(x-y)]
We factored out a minus from the second bracket. I chose the second bracket arbitrarily... You can chose the 1st bracket if you want.
Now when those two minus interact... They became Positive(From rules of sign Multiplication)
3x(x-y) + p(x-y)
Now factor out (x-y) from both
(x-y) [ 3x + p]
So that's our answer!!
(x-y)[ 3x + p ].