1) =(x^2-x+6x-6-x^2-x+6x+6)/(x^2-1)=10x/(x^2-1)
2) (3-b)/(b•(b-3))=-1/b
3) (4c^2-1-5c^2+1)/(2c-1)=-c^2/(2c-1)
4)=(2a^2-a^2-3a)/(2a•(a-3)•(a+3))=1/(2a+6)
Х= -3,5
(х+4)^2-(х-3)(х+2)=х^2+8х+16-х^2-2х+3х+6=9х+32=9×(-3,5)+32= -31,5+32=0,5
7х²-7 = 7(х²-1)= 7(х-1)(х+1)
а³-64а = а (а²-64)= а(а-8)(а+8)
5а³-5в³= 5(а³-в³) = 5 (а-в)(а²+ав+в²)
х²+2ху+у²-z² = (x-y)²-z² = (x-y-z)(x-y+z)
(-0,6)³=-0,216
(-0,6)ˇ6 ≥0
-0,6 -- -0,216 -- (-0,6)ˇ6