Если написано правильно то конечное уравнение выглядит так-> 43а-138-15аб
Пусть х - одна часть, тогда
S=4x*5x=20x^2=320
20x^2=320
2x^2=32
x^2=16
x=4
a=16 см
b=20 см
▪уменьшаемое - вычитаемое = разность
![уменьшаемое \: - (3 {x}^{2} - 2x) = 5 {x}^{2} - 6x \\ уменьшаемое \: = 5 {x}^{2} - 6x + 3 {x}^{2} - 2x \\ уменьшаемое = 8 {x}^{2} - 8x](https://tex.z-dn.net/?f=%D1%83%D0%BC%D0%B5%D0%BD%D1%8C%D1%88%D0%B0%D0%B5%D0%BC%D0%BE%D0%B5+%5C%3A++-+%283+%7Bx%7D%5E%7B2%7D++-+2x%29+%3D+5+%7Bx%7D%5E%7B2%7D++-+6x+%5C%5C++%D1%83%D0%BC%D0%B5%D0%BD%D1%8C%D1%88%D0%B0%D0%B5%D0%BC%D0%BE%D0%B5+%5C%3A++%3D+5+%7Bx%7D%5E%7B2%7D++-+6x+%2B+3+%7Bx%7D%5E%7B2%7D++-+2x+%5C%5C+%D1%83%D0%BC%D0%B5%D0%BD%D1%8C%D1%88%D0%B0%D0%B5%D0%BC%D0%BE%D0%B5+%3D+8+%7Bx%7D%5E%7B2%7D++-+8x)
Проверка:
![8 {x}^{2} - 8x - (3 {x}^{2} - 2x )= 8 {x}^{2} - 8x - 3 {x}^{2} + 2x = 5 {x}^{2} - 6x](https://tex.z-dn.net/?f=8+%7Bx%7D%5E%7B2%7D++-+8x+-+%283+%7Bx%7D%5E%7B2%7D+++-++2x+%29%3D+8+%7Bx%7D%5E%7B2%7D++-+8x+-+3+%7Bx%7D%5E%7B2%7D++%2B+2x+%3D+5+%7Bx%7D%5E%7B2%7D++-+6x)
Ответ:
К прошлому вопросу см. фото
Объяснение:
Насчёт волка ответ да, их используют в цирках
![sin(2x)=-\frac{1}{2}\\\\ 2x=-\frac{\pi}{6}+2\pi n,\ n\in Z\ \ \ or\ \ \ 2x=-\frac{5\pi}{6}+2\pi n,\ n\in Z\\\\ x=-\frac{\pi}{12}+\pi n,\ n\in Z\ \ \ or\ \ \ x=-\frac{5\pi}{12}+\pi n,\ n\in Z\\\\](https://tex.z-dn.net/?f=sin%282x%29%3D-%5Cfrac%7B1%7D%7B2%7D%5C%5C%5C%5C+2x%3D-%5Cfrac%7B%5Cpi%7D%7B6%7D%2B2%5Cpi+n%2C%5C+n%5Cin+Z%5C+%5C+%5C+or%5C+%5C+%5C+2x%3D-%5Cfrac%7B5%5Cpi%7D%7B6%7D%2B2%5Cpi+n%2C%5C+n%5Cin+Z%5C%5C%5C%5C+x%3D-%5Cfrac%7B%5Cpi%7D%7B12%7D%2B%5Cpi+n%2C%5C+n%5Cin+Z%5C+%5C+%5C+or%5C+%5C+%5C+x%3D-%5Cfrac%7B5%5Cpi%7D%7B12%7D%2B%5Cpi+n%2C%5C+n%5Cin+Z%5C%5C%5C%5C)
входящие в интервал
![[-\frac{\pi}{2};\ \pi]](https://tex.z-dn.net/?f=%5B-%5Cfrac%7B%5Cpi%7D%7B2%7D%3B%5C+%5Cpi%5D)
решения:
![-\frac{\pi}{12},\ -\frac{\pi}{12}+\pi,\ -\frac{5\pi}{12},\ -\frac{5\pi}{12}+\pi\\\\ -\frac{\pi}{12},\ \frac{11\pi}{12},\ -\frac{5\pi}{12},\ \frac{7\pi}{12}\\\\](https://tex.z-dn.net/?f=-%5Cfrac%7B%5Cpi%7D%7B12%7D%2C%5C+-%5Cfrac%7B%5Cpi%7D%7B12%7D%2B%5Cpi%2C%5C+-%5Cfrac%7B5%5Cpi%7D%7B12%7D%2C%5C+-%5Cfrac%7B5%5Cpi%7D%7B12%7D%2B%5Cpi%5C%5C%5C%5C%0A-%5Cfrac%7B%5Cpi%7D%7B12%7D%2C%5C+%5Cfrac%7B11%5Cpi%7D%7B12%7D%2C%5C+-%5Cfrac%7B5%5Cpi%7D%7B12%7D%2C%5C+%5Cfrac%7B7%5Cpi%7D%7B12%7D%5C%5C%5C%5C)
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![cos(4x)=\frac{\sqrt{2}}{2}\\\\ 4x=\pm\frac{\pi}{4}+2\pi n,\ n\in Z\\\\ x=\pm\frac{\pi}{16}+\frac{\pi n}{2},\ n\in Z\\\\](https://tex.z-dn.net/?f=cos%284x%29%3D%5Cfrac%7B%5Csqrt%7B2%7D%7D%7B2%7D%5C%5C%5C%5C+4x%3D%5Cpm%5Cfrac%7B%5Cpi%7D%7B4%7D%2B2%5Cpi+n%2C%5C+n%5Cin+Z%5C%5C%5C%5C+x%3D%5Cpm%5Cfrac%7B%5Cpi%7D%7B16%7D%2B%5Cfrac%7B%5Cpi+n%7D%7B2%7D%2C%5C+n%5Cin+Z%5C%5C%5C%5C)
входящие в интервал
![[0;\ \pi]](https://tex.z-dn.net/?f=%5B0%3B%5C+%5Cpi%5D)
решения:
![\frac{\pi}{16},\ \frac{\pi}{16}+\frac{\pi}{2},\ -\frac{\pi}{16}+\frac{\pi}{2},\ -\frac{\pi}{16}+\pi\\\\ \frac{\pi}{16},\ \frac{9\pi}{16},\ \frac{7\pi}{16},\ \frac{15\pi}{16}\\\\](https://tex.z-dn.net/?f=%5Cfrac%7B%5Cpi%7D%7B16%7D%2C%5C+%5Cfrac%7B%5Cpi%7D%7B16%7D%2B%5Cfrac%7B%5Cpi%7D%7B2%7D%2C%5C+-%5Cfrac%7B%5Cpi%7D%7B16%7D%2B%5Cfrac%7B%5Cpi%7D%7B2%7D%2C%5C+-%5Cfrac%7B%5Cpi%7D%7B16%7D%2B%5Cpi%5C%5C%5C%5C+%5Cfrac%7B%5Cpi%7D%7B16%7D%2C%5C+%5Cfrac%7B9%5Cpi%7D%7B16%7D%2C%5C+%5Cfrac%7B7%5Cpi%7D%7B16%7D%2C%5C+%5Cfrac%7B15%5Cpi%7D%7B16%7D%5C%5C%5C%5C)