Question

Daca nu ma puteti ajuta va rog sa nu comentati!

Answer 1

4) a) $x^{2}$+6xy+9$y^{2}$+$x^{2}$-9$y^{2}$=
=2$x^{2} + 6xy$
  b) $16 x^{2} -24x+9+ 5x^{2}-15x=21 x^{2} -39x+9$
  c) $1+2x+ x^{2} +4+4x+ x^{2} +9+6x+ x^{2} =3 x^{2} +12x+14$
  d)$x^{4} +2 x^{2}y+ y^{2} - x^{4} +2 x^{2} y- y^{2} =4 x^{2} y$