<span>b</span>₁ = <span>х - 1
b</span>₂ = <span>3х - 5
b</span>₃ = <span>9х - 19
</span><span>
b</span>₃ : b₂ = b₂ : b₁<span>
(9х - 19)/(3х-5) = (3х-5)/(х-1)
(9x-19)(x-1) = (3x-5)</span>²
<span>9x</span>² - 9x - 19x + 19 = 9x² - 30x + 25
<span>9x</span>² - 28x + 19 - 9x² + 30x - 25 = 0
<span>2x - 6 = 0
2x = 6
x = 3
Ответ: при х=3
</span>
75^20 = (25*3)^20 = 25^20*3^20= 5^40*3^20
45^10*5^30 = (5*9)10*5^30 = 5^10*9^10*5^30 = 5^40*9*10 = 5^40*3^20
9y²-12xy-45x²=(3y)²-2*3y*2x+4x²-4x²-45x²=(3y-2x)²-49x²=(3y-2y)²-(7x)²=
=(3y-2x-7x)(3y-2x+7x)=(3y-9x)(3y+5x).
Ответ:
Функция квадратичная, касается в точке 0