-6a^2+3a^2-5ab+5ab+b^2-b^2=-3a^2=-3*(-2/3)^2=-4/3
2*(1+сos4x)/2 *3sin4x+4*(1-cos4x)/2=0
1+cos4x+3sin4x+2-2cos4x=0
1-cos4x+3sin4x=0
2sin²2x+6sin2xcos2x=0/2cos²2x≠0
tg²2x+3tg2x=0
tg2x(tg2x+3)=0
tg2x=0⇒2x=πn⇒x=πn/2
tg2x=-3⇒2x=-arctg3+πn⇒x=-1/2arctg3+πn/2
=4-32y+64y^2+6y^2=4-32y+70y^2
<span>(х - 1)2 =x</span>²-2x+1<span>
(х + 4)2 =x</span>²+8x+16<span>
х2-25 =(x-5)(x+5)
(2а-1) (2а+1) =4a</span>²-1<span>
а2+4а+4 =(a+2)</span>²<span>
(3а-1)2 =9a</span>²-6a+1<span>
16-4х2 =(4-2x)(4+2x)
25х2-10х+1=(5x-1)</span>²
<span>Пишите, если что не так</span>