Question

раскрыть скобки (2x-y-3)^2+(x-3y-1)^2

Answer 1

(2x-y-3)²+(x-3y-1)²=(2x-y)²-6(2x-y)+9+

(x-3y)²-2(x-3y)+1=4x²-4xy+y²-12x+6y+9+

x²-6xy+9y²-2x+6y+1=5x²+10y²-10xy-14x+12y+10