А-8х / а : ах-8х² / а² = а-8х / а : х(а-8х) / а² = а-8х / а * а² / х(а-8х) = а/х
а/х = 27/45 = 3/5 = 0,6
по т Виета х1+х2=-р х1*х2= q
x^2-(a+b)x+ab=0
<span>(3a-b)(a-7b)+a(22b-2a)=3a²-21ab-ab+7b²+22ab-2a²=a²+7b²
</span>3c(4c-5)-(c-8)(c-7)=12c²-15c-(c²-7c-8c+56)=12c²-15c-(c²-15c+56)=
=12c²-15c-c²+15c-56=11c²-56
<span>(y-5)²-(5-у)(5+у)</span>=y²-10y+25-(25-y²)=y²-10y+25-25+y²=2y²-10y