Вправи: 201

201. Виконай дії:

а) 1x2+ 3xy + 29y2- x2 + 12x-6y = 1\6y-2xx(x+3y) + 2\2x3y-x(3y+x) + 1\-x(3y+x)2(x-3y) = 3y-2x+4x-x(3y+x)2x3y-x(3y+x) = 6y+2x-3xy- x22x3y-x(3y+x) = 23y+x- x(3y+x)2x3y-x(3y+x) = 3y+x(2-x)2x3y-x(3y+x) = 2-x2x3y-x;

б) 7- x2x3- 1 + 3x+5x2+ x+1 + 21-x = 7- x2x-1(x2+ x+1) + 3x+5x2+ x+1 + 21-x = 7- x2+ x-13x+5- 2(x2+ x+1)x-1(x2+ x+1) = 7- x2+ 3x2+ 5x-3x-5-2x2- 2x-2x-1(x2+ x+1) = 0.