1
1)2a²-a-3=2(a-1,5)(a+1)=(2a-3)(a+1)
D=1+24=25
a1=(1-5)/4=-1
a2=(1+5)/4=1,5
a²+5a=6=(a+2)(a+3)
a1+a2=-5 U a1*a2=6⇒a1=2 U a2=3
(2a-3)(a+1)/(a+2)(a+3):(2a-3)/(a-2)=(2a-3)(a+1)/(a+2)(a+3)*(a-2)/(2a-3)=
=(a=1)(a-2)/(a+3)(a+2)
2)(a+2)/(a-2)*(a+1)(a-2)/(a+3)(a+2)=(a+1)/(a+3)
2
1)2+1/b=(2b+1)/b
2)(2b+1)/b:2(2b+1)²/b(b-4)=(2b+1)/b*b(b-4)/[2(2b+1)²]=(b-4)/[2(2b+1)]
3)(b-4)/[2(2b+1)]*(2b+1)/b=(b-4)/2b