C²-1=c²-1²=(c+1)(c-1)
x²-4x+4=(x-2)(x-2)=(x-2)²
25y²-4)=(5y)²-2²=(5y+2)(5y-2)
36a²-60ab+25b²=(6a)²-2.6a.5b+(5b)²=(6a-5b)(6a-5b)=(6a-5b)²
<span>представьте в виде произведения ( x-4)^2- 25x^2
</span>( x-4)^2- 25x^2=(x - 4-5x)(x-4+5x)=(-4x-4)(6x-4)=
= - 4(x+1)2(3x-2)= - 8(<span>x+1)2(3x-2)</span>
Sin210=-0.5
ctg135=1/tg135
tg135=-1
4*(-0.5)-(-1)=-2+1=-1
x²+8x+15>0
x²+8x+15=0, a=1,b=8, c= 15
D=b²-4ac=8²-4×1×15=64-60=4
x1=-b-√D/2 = -8-√4/2=-8-2/2=-10:2=-5
x2=-b+√D /2=-8+√4/2=-8+2/2=-3
X+y-x²-xy=(x+y)-x(x+y)=(x+y)(1-x)
4ab²+5ab+a=4ab²+4ab+ab+a=4ab(b+1)+a(b+1)=(b+1)(4ab+a)=a(4b+1)(b+1)
(y-5)(y+11)=0
y-5=0 => y1=5
y+11=0 => y2=-1
t²+12t=0
t(t+12)=0
t1=0
t+12=0 => t2=-12
-x²+25=0
x²-25=0
(x-5)(x+5)=0
x-5=0 => x1=5
x+5=0 => x2=-5