Ответ:
Объяснение:
1.
![1|)x^{2} -4x+22=x^{2} +8x-4x+32=x*(x+8)-4(x+8)=(x+8)*(x-4).\\2)4x^{2} -15x+9=4x^{2} -12x-3x+9=4x*(x-3)-3(x-3)=(x-3)*(4x-3). 1|)x^{2} -4x+22=x^{2} +8x-4x+32=x*(x+8)-4(x+8)=(x+8)*(x-4).\\2)4x^{2} -15x+9=4x^{2} -12x-3x+9=4x*(x-3)-3(x-3)=(x-3)*(4x-3).](https://tex.z-dn.net/?f=1%7C%29x%5E%7B2%7D%20-4x%2B22%3Dx%5E%7B2%7D%20%2B8x-4x%2B32%3Dx%2A%28x%2B8%29-4%28x%2B8%29%3D%28x%2B8%29%2A%28x-4%29.%5C%5C2%294x%5E%7B2%7D%20-15x%2B9%3D4x%5E%7B2%7D%20-12x-3x%2B9%3D4x%2A%28x-3%29-3%28x-3%29%3D%28x-3%29%2A%284x-3%29.)
2.
x⁴-35x-36=0
Пусть х²=t≥0 ⇒
t²-35t-36=0 D=1369 √D=37
t₁=x²=-1 ∉
t₂=x²=36
x₁=-6 x₂=6.
3.
![\frac{4a^{2} +a-3}{a^{2}-1 } =\frac{4a^{2}+4a-3a-3 }{a^{2}-1 } =\frac{4a*(a+1)-3*(a+1)}{a^{2}-1 }=\frac{(4a-3)*(a+1)}{(a+1)*(a-1)}=\frac{4a-3}{a-1} . \frac{4a^{2} +a-3}{a^{2}-1 } =\frac{4a^{2}+4a-3a-3 }{a^{2}-1 } =\frac{4a*(a+1)-3*(a+1)}{a^{2}-1 }=\frac{(4a-3)*(a+1)}{(a+1)*(a-1)}=\frac{4a-3}{a-1} .](https://tex.z-dn.net/?f=%5Cfrac%7B4a%5E%7B2%7D%20%2Ba-3%7D%7Ba%5E%7B2%7D-1%20%7D%20%3D%5Cfrac%7B4a%5E%7B2%7D%2B4a-3a-3%20%7D%7Ba%5E%7B2%7D-1%20%7D%20%3D%5Cfrac%7B4a%2A%28a%2B1%29-3%2A%28a%2B1%29%7D%7Ba%5E%7B2%7D-1%20%7D%3D%5Cfrac%7B%284a-3%29%2A%28a%2B1%29%7D%7B%28a%2B1%29%2A%28a-1%29%7D%3D%5Cfrac%7B4a-3%7D%7Ba-1%7D%20%20.)
4.
![\frac{10}{x^{2}-100 } +\frac{x-20}{x^{2}+10x } -\frac{5}{x^{2}-10x } =0\\\frac{10}{(x-10)(x+10)}+\frac{x-20}{x*(x+10)}-\frac{5}{x*(x-10)} =0\\ \frac{10}{x^{2}-100 } +\frac{x-20}{x^{2}+10x } -\frac{5}{x^{2}-10x } =0\\\frac{10}{(x-10)(x+10)}+\frac{x-20}{x*(x+10)}-\frac{5}{x*(x-10)} =0\\](https://tex.z-dn.net/?f=%5Cfrac%7B10%7D%7Bx%5E%7B2%7D-100%20%7D%20%2B%5Cfrac%7Bx-20%7D%7Bx%5E%7B2%7D%2B10x%20%7D%20-%5Cfrac%7B5%7D%7Bx%5E%7B2%7D-10x%20%7D%20%3D0%5C%5C%5Cfrac%7B10%7D%7B%28x-10%29%28x%2B10%29%7D%2B%5Cfrac%7Bx-20%7D%7Bx%2A%28x%2B10%29%7D-%5Cfrac%7B5%7D%7Bx%2A%28x-10%29%7D%20%20%3D0%5C%5C)
ОДЗ: х-10≠0 x≠10 x+10≠0 x≠-10.
![10*x+(x-20)*(x-10)-5*(x+10)=0\\10x+x^{2} -30x+200-5x-50=0\\x^{2} -25x+150=0\\D=-1775. 10*x+(x-20)*(x-10)-5*(x+10)=0\\10x+x^{2} -30x+200-5x-50=0\\x^{2} -25x+150=0\\D=-1775.](https://tex.z-dn.net/?f=10%2Ax%2B%28x-20%29%2A%28x-10%29-5%2A%28x%2B10%29%3D0%5C%5C10x%2Bx%5E%7B2%7D%20-30x%2B200-5x-50%3D0%5C%5Cx%5E%7B2%7D%20-25x%2B150%3D0%5C%5CD%3D-1775.)
Уравнение не имеет действительных корней.
5.
Пусть скорость первого автомобиля - х. ⇒
Скорость второго автомобиля - х-10.
![\frac{300}{x-10}-\frac{300}{x}=1\\ 300x-300x+3000=x*(x-10)\\x^{2} -10x-3000=0\\D=10000;\sqrt{D} =100 \frac{300}{x-10}-\frac{300}{x}=1\\ 300x-300x+3000=x*(x-10)\\x^{2} -10x-3000=0\\D=10000;\sqrt{D} =100](https://tex.z-dn.net/?f=%5Cfrac%7B300%7D%7Bx-10%7D-%5Cfrac%7B300%7D%7Bx%7D%3D1%5C%5C%20%20300x-300x%2B3000%3Dx%2A%28x-10%29%5C%5Cx%5E%7B2%7D%20-10x-3000%3D0%5C%5CD%3D10000%3B%5Csqrt%7BD%7D%20%3D100)
x₁=-45 ∉ x₂=55.
55-10=45.
Ответ: скорость первого автомобиля 55 км/ч,
скорость второго автомобиля 45 км/ч.