<span>(5а-2)(4а+3)-20а</span>²=20а²+15а-8а-6-20а²=7а-6
если <span>а =-3,то</span>
<span>7а-6=7*(-3)-6=21-6=27</span>
Sqrt(6+4sqrt2)=sqrt(2+2*2*sqrt2+4)=sqrt((srtr2)^2+2*2*sqrt2+2^2)=sqrt((sqrt2+2)^2)=sqrt2+2
Ответ:кк2+2
( X - 5 )*( X - 3 ) = 0
X^2 - 3X - 5X + 15 = 0
X^2 - 8X + 15 = 0
1)36a12b7/54a8b11=6•3•7/9•2•11=6•21/18•11=21/3•11=21/33=7/11
2)18mn-27n/9mn=9n(2m-3)/9mn=2m-3/m
3)3c-15/c^2-25=3(c-5)/(c-5)(c+5)=3/c+5