15 × (1/5)² - 8×1/5 = 15/25 - 8/5 = 3/5-8/5=-5/5=-1
-1+(-a+√a)a/√a+√a
-1+-a²+a√a/2√a
-a²-1+a√a/2√a
-√aa²-√a*1+√aa√a/2*a
-a²√a-√a+√a√a/2a
-a²√a-√a+aa/2a
a²-a²√a-√a/2a
( a -ab) : (a)=a( 1 -a) : (a)=1 -a
(x - xy) : ( - x)=(xy-x ) : (x)=x(y-1 ) : (x)=y-1
( - m - mn) : m =m(-1-n) : m=-1-n
( - c + cd) :( - c)
=( cd - c) :( - c)=c( d - 1) :( - c)=d - 1