Zadania w załączniku . Za odpowiedź bezbłędną daje najlepszą i 5 gwiazdek.

zadanie 20 c) (x+4)²+(x+8)/2 = 0,5x(2x-6)+3(x+1) x²+8x+16+0,5x+4 = x²-3x+3x+3 8,5x+20 = 3 8,5x = 3-20 8,5x = -17 |:8,5 x = -2 d) (2x-1)²+5 = 4x(x-2)-2(2x+1) 4x²-4x+1+5 = 4x²-8x-4x-2 -4x+6 = -12x-2 -4x+12x = -2-6 8x = -8 |:8 x = -1 zadanie 21 a) (x-3)²-(x-3)/2 = (x+1)²+x x²-6x+9-(0,5x-1,5) = x²+2x+1+x -6x+9-0,5x+1,5 = 3x+1 -6,5x+10,5 = 3x+1 -6,5x-3x = 1-10,5 -9,5x = -9,5 |:(-9,5) x = 1 b) (2x-3)²+0,5(x-10) = (2x-4)(2x+4)-2(x-10) 4x²-12x+9+0,5x-5 = 4x²-16-2x+20 -11,5x+4 = -2x+4 -11,5x+2x = 4-4 -9,5x = 0 |:(-9,5) x = 0 c) (x+1)(x-1)-1/3(2x-6) = (x-5)²+0,5(3x+5)-3 x²-1-2/3x+2 = x²-10x+25+1,5x+2,5-3 -2/3x+1 = -8,5x+24,5 -4/6x+8i3/6x = 24,5-1 7i5/6x = 23i1/2 47/6x = 47/2 |:47/6 x = 6/2 x = 3 d) (4+x)²+1/3(x+5) = (x-1)²+2x 16+8x+x²+1/3x+1i2/3 = x²-2x+1+2x 8i1/3x+17i2/3 = 1 8i1/3x = 1-17i2/3x 8i1/3x = -16i2/3 |:8i1/3 x = -2