doprowadz wyrazenia do najprostrzej postaci i oblicz ich waryosci dla podanych zmiennych ; a) (2x-3)(x+5)-2(x+1)(x+3) dla x=-3.5 b)3(x-4)(x-1)-(2x+3)(2-x) dla x=1/2 c) (3x-5)(x+2)-2 (x+1)(2x-3) dla x=  -1 1/2  d) 3 (3x-1) (4+2x)-4(x+3)(4x-1) dla x=-2 1/2

a) (2x-3)(x+5)-2(x+1)(x+3)=2x²+10x-3x-15-2(x²+3x+x+3)=2x²+10x-3x-15-2x²-6x-2x-6=-2x-21   dla x=-3.5        -2*(-3,5)-21=-14 b)3(x-4)(x-1)-(2x+3)(2-x)=3*(x²-x-4x+4)-(4x-2x²+6-3x)=3x²-15x+12-4x+2x²-6+3x=5x²-12x+6   x=1/2   5*1/2²-12*1/2+6=5/4-6+6=5/4 c) (3x-5)(x+2)-2 (x+1)(2x-3)=3x²+6x-5x-10-2(2x²-3x+2x-3)=3x²+x-10-4x²+6x-4x+6=-x²+3x-4     dla x=  -1 ½        -(-1 ½)²+3*1 ½-4=-9/4+9/2-4=-9/4+18/4-4=9/4-4=-1¾ d) 3 (3x-1) (4+2x)-4(x+3)(4x-1)=3*(12x+6x²-4-2x)-4*(4x²-x+12x-3)=30x+18x²-12-16x²-44x+12=2x²-14x     dla x=-2½       2*(-2½)²-14*(-2½)=2*25/4-14*(-5/2)=25/2+35=47½

a) (2x-3)(x+5)-2(X+1)(x+3)= 2x^2 +10x -3x -15 -2x^2 -6x-2x-6 = -x-21       dla x = -3,5     - (-3,5) -21 = 3,5 - 21 = - 17,5   b) 3(x-4)(x-1)-(2x+3)(2-x)= 3x^2 -3 -4x +4 -4x +2x^2+6-3x = 5x^2 +6 -16x      dla x = 1/2      5* (1/2)^2 + 6 - 16*1/2 = 5*1/4 + 6-16/2 = 5/4+6-8= 7 i1/4 -7i 4/4 = - 3/4   c) (3x-5)(x+2)-2(x+1)(2x-3) =3x^2 +6x -5x-10 -4x^2+6x -4x +6 = x^2 +3x -4     dla x = -1 i 1/2 = - 3/2          (-3/2)^2 +3*(-3/2)-4= 9/4 -9/2-4= 9/4 -18/4 - 4 = -9/4-4=-2i1/4-4= -6i1/4   d) 3(3x-1)(4+2x)-4(x+3)(4x-1)=36x +18x^2 -12 -6x -16x^2 +4x -48x +12 = -14x +2x^2           dla x = -2i1/2 = - 5/2       -14 (-5/2) +2(-5/2)^2 = -7(-5/1)+2(25/4)= 35/1 +50/4=35+12i2/4=47 i 1/2