1
1)(a+3)²/(b-4)*(b-4)(b+4)/(a-3)(a+3)=(a+3)(b+4)/(a-3)
2)(a+3)(b+4)/(a-3)-(4a+3b)/(a-3)=(ab+4a+3b+12-4a-3b)/(a-3)=(ab+12)/(a-3)
2
1)5a/(a+1)²*(a+1)/20=a/4(a+1)
2)(a-1)/4(a+1)+6/3(a-1)(a+1)-a/4(a-1)=[(a-1)²+2*4-a(a+1)]/4(a²-1)=
=(a²-2a+1+8-a²-a)/4(a²-1)=(9-3a)/4(a²-1)=(9-3a)/(4a²-4)
3
домножим на 6
(3x+1)²-3x(3x+5)=2(x-3)
9x²+6x+1-9x²-15x-2x+6=0
-11x=-7
x=7/11
4
(x-2)(x+2)/x*1/(x+2)-2/x+4=(x-2)/x-2/x+4=(x-2-2+4x)/x=(5x-4)/x=
=(-1-4)/(-0,2)=5/0,2=25