Oblicz wartości liczbowe wyrażeń :   a) 2(x do potęgi 2 -3x+1) - 2(x do potęgi 2 -5x-2) =       dla x=2 b)y(2yx + x) - y( x- 2xy + x) =         dla x=-1y=1/2      

a) 2(x^2-3x+1)-2(x^2-5x-2)=2x^2-6x+2-2x^2+10x+4=4x+6=4*2+6=8+6=14 b) y(2yx+x)-y(x-2xy+x)=2xy^2+xy-xy+2xy^2-xy=4xy^2-xy=4*(-1)*(1/2)^2-(-1)*(1/2)=(-4)*(1/4)+1/2=(-1)+1/2=(-1/2)

a)2([latex]2^{2}[/latex]-(3*2)+1)-2([latex]2^{2}[/latex]-(5*2)-2=16-12+2-16+20+4=14 b)y(2yx + x) - y( x- 2xy + x) =1/2(2*1/2*(-1)+(-1))-1/2(-1-2*(-1)*1/2+(-1)=1/2(-1+(-1))-1/2(-1+1+(-1))=-1/2-1/2+1/2-1/2-1/2=-1/6