Question

упростите выражение: (х+у)^2/6 + (х-у)^2/12 - х^2-у^2/4.

Answer 1

 (х+у)²/6 + (х-у)²/12 - х²-у²/4
x²+2xy+y²/6+x²-2xy+y²/12-x²-y²/4
2(x²+2xy+y²)+x²-2xy+y²-3(x²-y²)
2x²+4xy+2y²+x²-2xy+y²-3x²+3y²/12
0+2xy+6y²/12
2(xy+3y²)/12
xy+3y²/6