![\frac{2x^2+3x}{3-x}= \frac{x-x^2}{x-3} \\ \\ x \neq 3 \\ \\ \frac{2x^2+3x}{3-x}= \frac{-(x-x^2)}{3-x} \\ \\ 2x^2+3x=-x+x^2 \\ 2x^2-x^2+3x+x=0 \\ x^2+4x=0 \\ x(x+4)=0 \\ ](https://tex.z-dn.net/?f=+%5Cfrac%7B2x%5E2%2B3x%7D%7B3-x%7D%3D+%5Cfrac%7Bx-x%5E2%7D%7Bx-3%7D+%5C%5C+%0A+%5C%5C+%0Ax+%5Cneq+3+%5C%5C+%0A+%5C%5C+%0A+%5Cfrac%7B2x%5E2%2B3x%7D%7B3-x%7D%3D+%5Cfrac%7B-%28x-x%5E2%29%7D%7B3-x%7D+%5C%5C+%0A+%5C%5C+%0A2x%5E2%2B3x%3D-x%2Bx%5E2+%5C%5C+%0A2x%5E2-x%5E2%2B3x%2Bx%3D0+%5C%5C+%0Ax%5E2%2B4x%3D0+%5C%5C+%0Ax%28x%2B4%29%3D0+%5C%5C+%0A++++)
1) x=0
2) x+4=0
x= -4
0+(-4)= -4 - сумма корней.
-4∈(-5; -3)
Ответ:
1
1) x ∈ (-∞;-2)∪(-2;+∞);
2) x ∈ [-10;10]
3
1)Четная
Объяснение:
y(x)=5x²+4x⁶
y(-x)=5(-x)²+4(-x)⁶=5x²+4x⁶=y(x)
y(-x)=y(x)
Чётная
Tg( 10π/3) = tg(3π + π/3) = tgπ/3 = √3
Сперва выполняется умножение
![\frac{a}{a^2-c^2}* \frac{a+c}{2ac}= \frac{a}{(a-c)(a+c)}* \frac{a+c}{2ac}= \frac{a(a+c)}{(a-c)(a+c)*2ac}= \frac{1}{2c(a-c)}](https://tex.z-dn.net/?f=+%5Cfrac%7Ba%7D%7Ba%5E2-c%5E2%7D%2A+%5Cfrac%7Ba%2Bc%7D%7B2ac%7D%3D+%5Cfrac%7Ba%7D%7B%28a-c%29%28a%2Bc%29%7D%2A+%5Cfrac%7Ba%2Bc%7D%7B2ac%7D%3D+%5Cfrac%7Ba%28a%2Bc%29%7D%7B%28a-c%29%28a%2Bc%29%2A2ac%7D%3D+%5Cfrac%7B1%7D%7B2c%28a-c%29%7D+++)
теперь деление:
![\frac{1}{2c(a-c)}: \frac{1}{a-c}=\frac{1}{2c(a-c)}* \frac{a-c}{1}=\frac{1*(a-c)}{2c(a-c)}= \frac{1}{2c}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2c%28a-c%29%7D%3A+%5Cfrac%7B1%7D%7Ba-c%7D%3D%5Cfrac%7B1%7D%7B2c%28a-c%29%7D%2A+%5Cfrac%7Ba-c%7D%7B1%7D%3D%5Cfrac%7B1%2A%28a-c%29%7D%7B2c%28a-c%29%7D%3D+%5Cfrac%7B1%7D%7B2c%7D++)
<span>Через 17,5 минут масса изотопа будет равна 12,5 мг</span>