-38x+15=-21x-36
-38x+21x=-36-15
-17x=-51
x=-51/(-17)
x=3;
-38*3+15=-114+15=-99.
Ответ:x=3;y=-99.
<span>5*(x+2)=9
5х+10=9
5х=9-10
5х=-1
х=-1/5
х=-0,2</span>
Нас учат так:
Если х=0,5,то у=6х+19=6×0,5+19=22.
a
![3^{1-2x} = 45x\\3 = 9^{x}\cdot 9\cdot 5 x\\\frac{3}{45} = x9^x | \ln9\\\frac{3\ln(9)}{45} = x\ln(9)\,e^{x\ln(9)}](https://tex.z-dn.net/?f=3%5E%7B1-2x%7D+%3D+45x%5C%5C3+%3D+9%5E%7Bx%7D%5Ccdot+9%5Ccdot+5+x%5C%5C%5Cfrac%7B3%7D%7B45%7D+%3D+x9%5Ex+%7C+%5Cln9%5C%5C%5Cfrac%7B3%5Cln%289%29%7D%7B45%7D+%3D+x%5Cln%289%29%5C%2Ce%5E%7Bx%5Cln%289%29%7D)
Введём W-функцию Ламберта. Её свойство:
.
Тогда,
![x \ln(9) = W(\frac{3\ln(9)}{45}) \Rightarrow x = \frac{W(\frac{3\ln(9)}{45})}{\ln(9)}](https://tex.z-dn.net/?f=x+%5Cln%289%29+%3D+W%28%5Cfrac%7B3%5Cln%289%29%7D%7B45%7D%29+%5CRightarrow+x+%3D+%5Cfrac%7BW%28%5Cfrac%7B3%5Cln%289%29%7D%7B45%7D%29%7D%7B%5Cln%289%29%7D)
б
![2^{x+1} = 5^{1 -3x}](https://tex.z-dn.net/?f=2%5E%7Bx%2B1%7D+%3D+5%5E%7B1+-3x%7D)
![2^{x+1} = 2^{(1 - 3x)\ln(5)}\\x + 1 = (1 - 3x)\ln(5)\\x + 3x\ln(5) = \ln(5) - 1\\x = \frac{\ln(5) - 1}{1 + 3\ln(5)}](https://tex.z-dn.net/?f=2%5E%7Bx%2B1%7D+%3D+2%5E%7B%281+-+3x%29%5Cln%285%29%7D%5C%5Cx+%2B+1+%3D+%281+-+3x%29%5Cln%285%29%5C%5Cx+%2B+3x%5Cln%285%29+%3D+%5Cln%285%29+-+1%5C%5Cx+%3D+%5Cfrac%7B%5Cln%285%29+-+1%7D%7B1+%2B+3%5Cln%285%29%7D)
треуголник равнобедренный=>высота является и медианой