Ответ:
Объяснение:
1. a) -3x(2-x)+(3x+1)(x-2) = -6x+3x^{2}+3x^{2}-6x+x-2 = 6x^{2}-11x-2
b) (x+5)4x-(2x+5)^{2} = 4x^{2}+20x-(4x^{2}+20x+25) = 4x^{2}+20x-4x^{2}-20x-25 = -25
в) 3(2x-1)^{2}+12x = 3(4^{2}-4x+1)+12x = 12^{2}-12x+3+12x = 12^{2}+3
г) (x+3)^{2}-(x-2)(x+2) = x^{2}+6x+9-(x^{2}-4) = x^{2}+6x+9-x^{2}+4 = 6x+13
д) (x-5)^{2}-4(x+5)^{2} = x^{2}-10x+25-4(x^{2}+10x+25) = x^{2}-10x+25-4x^{2}-40x-100 = -3x^{2}-50x-75 = 3x^{2}+50x+75