A) 0,25x²-4x+16=(0,5x-4)²= (0,5*(-12)-4)²=(-6-4)²=-10²= 100
b) 64x²+1,6+0,01=64*(-0,2)²+1,61= 64*0,04+1,61= 4,17
1.
1) m^3+125n^3=(m+5n)(m^2-5mn+25)
2) xy^2-16x^3=x(y^2-16x^2)=x(y-4x)(y+4x)
3) -5x^2+30x-45=-5(x^2-6x+9)=-5(x-3)^2
4) 7xy-42x+14y-84=7(xy-6x+2y-12)=
=7(-6(x+2)+y(x+2))=7(x+2)(y-6)
5) 10000-c^4=(100-c^2)(100+c^2)
2.
b(b-3)(b+3)-(b-1)(b^2+b+1)=b(b^2-9)-(b^3-1)=b^3-9b-b^3+1=1-9b
3.
1) 81с^2-d^2+9c+d=(9c-d)(9c+d)+(9c+d)=(9c+d)(9c-d+1)
2) a^2+8ab+16b^2-1=(a+4b)^2-1=(a+4b-1)(a+4b+1)
3) ax^6-3x^6-ax^3+3x^3=x^3(ax^3-3x^3-a+3)=-3(x^3-1)+a(x^3-1)=(x^3-1)(a-3)
4) 25-m^2-12mn-36n^2=25-(m^2+12mn+36n^2)=25-(m+6n)^2=(5-m-6n)(5+m+6n)
<span>tg умножить на <span>ctg=1</span></span>
<span><span>а)1</span></span>
<span><span>Б)3</span></span>
<span><span>В)1</span></span>
<span><span>Г)7</span></span>
д)7