Calculati, folosind formulele de calcul prescurtat: a) (x+2)(x-2)+(x+4)²-2x=? b) (2-x)²-(x+3)(x-3)-x(x-1)=? c) (x+5)²-2(x-5)(x+5)+x²=? d) (6-x)²-3(x+2)-5(x+1)=? As vrea rezolvarile complete, varog.
a) x²-4+x²+8x+16-2x=2x²-10x+12=2(x²-5x+6)=2(x-2)(x-3) b) 4-4x+x²-x²+9-x²+x=-x²-3x+13 c) (x+5)²-2(x-5)(x+5)+x²-10x+25+10x-25=(x+5)²-2(x-5)(x+5)+(x-5)²+10x-25=(x+5-x+5)²+10x-25=10+10x-25=10x-15=5(2x-3) d) 36-12x+x²-3x-6-5x-5=x²-20x+25
