zad 1.) (2x-4y)(2x+4y)+(2x+4y)²+(2x-4y)²-(x-3)(x+7)= stosuję wzory : 1) (a-b)(a+b) = a² -b² 2) (a +b)² = a² + 2ab + b² 3) (a -b)² = a² -2ab +b² 4x² - 16y² + 4x² + 16xy + 16y² + 4x² - 16xy + 16y² -(x²+4x -21)= = 12x² +16y² -x² -4x +21 = = 11x² + 16y² -4x +21 dla x= -⅓ dlay= 3 = 11*(-⅓)² + 16*3² -4*(-⅓) + 21= = 11/9 + 144 + 4/3 +21= = 11/9 +12/9 + 165 = = 23/9+ 165= = 2 i 5/9 + 165 = = 167 i 5/9 zad2). -(x-4)²= (3-x)(3+x) plus sprawdzenie -(x-4)²= (3-x)(3+x) /*(-1) (x -4)² = x² -9 x² - 8x +16 = x² -9 x² - 8x +16 - x² + 9 =0 - 8x +25 = 0 - 8x = -25 x = 25/8 Spr. L(25/8) = (25/8 -4)² = (3⅛ -4)² = (-⅞)² = 49/64 P(25/8) = ( 25/8-3)(25/8 +3)= ( 3⅛ - 3)( 3⅛ +3) = (⅛)(6⅛)=(⅛)(49/8)= 49/64 L(25/8) = P (25/8) zad3.) (x+½)²-(x-1)(x+1)=16 plus sprawdzenie x² + x +¼ -( x² -1) = 16 x² +x + ¼ - x² + 1 = 16 x = 16 -1¼ x = 14¾ x = 59/4 L(59/4) = (59/4 + ½)² - [ (59/4 )² -1] = = (59/4 +2/4)² -[ 3481/16 - 16/16]= = (61/4)² - [ 3465/16] = 3721/16 - 3465/16 = 256/16 = 16 P(59/4) = 16 L(59/4) = P(59/4)
