По теореме Виета
x1+x2=a
x1*x2=2a
a=5
4x^2 – 1=(2х-1)(2х+1)
25x^2 – 9y^2=(5х-3у)(5х+3у)
3x^2 – 6x=3х(х-2)
<span> 5by – y =у(5b-1)</span>
bx^2 - bу^2=b(x-y)(x+y)
5х+5у=5(x+y)
bc - bd=b(c-d)
ах^2 + 2аху + ау^2=a(x+y)²
ав^2 - 3в^2 + аву - 3ву=b(b+y)(a-3)
ab-a^2b=ab(1-a)
8m(a-3)+n(a-3)=(a-3)(8m+n)
(p^2-25)-q(p^2-25)=(p²-25)(1-q)=(p-5)(p+5)(1-q)
3а^2-3в^2=3(a-b)(a+b)
12а^2-4=4(3a²-1)
9x^2 + 18ху + 9у^2=9(x+y)²
-7p^2 + 28pq - 28q^2= -7(p²-4pq+4q²)= -7(p-2q)²
<span> 8x^3 - 8y^3= 8(x</span>³-y³)=9(x-y)(x²-xy+b²)
100^n/5^2n-1*4^n-2=25<em /><em />^n*4^n/5^2n*4^n-2=5^2n*4^n/5^2n-1*4^n-2=5^(2n-2n+1)*4^(n-n+2)=5^1*4^2=5*16=80
(c*d):(с+d)//////////////////////////