X⁵ - x² + x² - 1 = (x⁵ - x²) + (x² - 1) = x²(x³ - 1) + ( x - 1)(x+ 1) =
= x²( x - 1)(x² + x + 1) + ( x - 1)( x + 1) = ( x - 1)(x²(x²+x+1) + x + 1) =
= ( x - 1)( x⁴ + x³ + x² + x + 1)
1.а)х=-9 х=5
+ _ +
_________________________
-9 5
х∈(-≈;-9)U (5;≈)
б)x=3 x=-6
+ _ +
_________________________
-6 3
x∈(-6;3)
2.a) x(x-7)(x+7)=0⇒x=0,x=7,x=-7
б)2x²+6-17+3x-16=0
2x²+3x-27=0
D=9+216=225 √D=15 x1=(-3-15)/4=-4,5 x2=(-3+15)/4=3
в) х²=а
а²-17а+16=0 а1+а2=17 и а1*а2=16
а1=16⇒х²=16⇒х=4 и х=-4
а2=1⇒х²=1⇒х=1 и х=-1
3)D=t²-100<0
(t-10)(t+10)<0
t=10 t=-10
+ _ +
_______________________
-10 10
t∈(-10;10)
4)5x-2x²≥0
x(5-2x)≥0
x=0 x=2,5
_ + -
__________________________
0 2,5
x∈[0;2,5]
36*38=(37-1)(37+1)=37*37-1=3638
30a^3+35a^2b-40ab^2+5b^3
30a^5+35a^4b-40a^3b^2+5a^2b^3
30a^5+35a^5b-40a^4b^2+5a^3b^3
30a^4b^18+35a^3b^19-40a^2b^20+5ab^21
3a^8x+3.5a^2bx-4ab^2x+1/2b^3x
^число- степень числа