(x^3+3^3)/(x-3) - x^2 - 3x -9 =(x+3)(x^2-3x+9)/(x-3) -(x^2+3x+9)=
<u>(x+3)(x^2-3x+9) -(x^2+3x+9)*(x-3)</u> =
x-3
<u>x^3-3x^2+9x+3x^2-9x+27 - x^3+3x^2-3x^2+9x-9x+27</u>=
x-3
<u>
27 +27</u>=
x-3
<u>
54 </u>
x-3
Y=1/(-x²+ax-3) V(4:1/11)
1/(-16+4a-3)=1/11
4a-19=11
4a=11+19=30
a=30:4=7,5
y=1/(-x²+7,5x-3)
y`=-(-2x+7,5)/(-x²+7,5x-3)²=0
-2x=-7,5
x=7,5/2=3,75
y(3,75)=1:(-121/16+165/8-3)=1:(161/16)=16/161
/////////////////////////////////
/х²-у²=72
\х²+у=9
у=9-х²
х²-(9-х²)²=72
х²-81+18х²-х₄=72
19х²-х₄-81-72=0
19х²-х₄-153=0
х²=а
19а-а²-153=0
Д= 19²-4*153=361-612=-251 - Д<0 -нет корней