А)2*5у-7у=6
10у-7у=6
3у=6
у=2
х=5*2=10
Под б)вы уверены что правильно переписали?
Ответ прикреплен во вложении
У=кх+2
а)у=-х
у=-1*х;к1=-1
если параллельно.значит углавые коэффициенты равные
к=к1=-1
у=-х+2
б)у=кх+2
значит паралельно ось 0Х
к=0
у=2
в)у=кх+2
у=0;х=1
0=к+2
к=-2
у=-2х+2
Вариант 4 с-2
№1
а)(x+6)(x+2)<0 {приравниваем к нулю}
(x+6)(x+2)=0 {перемножаем скобки}
![x^{2} +2x+6x+12=0](https://tex.z-dn.net/?f=+x%5E%7B2%7D+%2B2x%2B6x%2B12%3D0)
![x^{2} +8x+12=0](https://tex.z-dn.net/?f=+x%5E%7B2%7D+%2B8x%2B12%3D0)
{и решаем через дискриминант}
D=
![(b) ^{2} -4*a*c](https://tex.z-dn.net/?f=%28b%29+%5E%7B2%7D+-4%2Aa%2Ac)
D=
![(8) ^{2} -4*1*12=16](https://tex.z-dn.net/?f=%288%29+%5E%7B2%7D+-4%2A1%2A12%3D16)
D=4
![x_{1,2} = \frac{-8 \frac{+}{-} 4}{2}](https://tex.z-dn.net/?f=+x_%7B1%2C2%7D+%3D+%5Cfrac%7B-8+%5Cfrac%7B%2B%7D%7B-%7D+4%7D%7B2%7D+)
![x_{2} = -2](https://tex.z-dn.net/?f=+x_%7B2%7D+%3D+-2)
{потом рисунок ниже}
б)
![x^{2} \geq 64x](https://tex.z-dn.net/?f=+x%5E%7B2%7D++%5Cgeq+64x)
![x^{2} -64x \geq 0](https://tex.z-dn.net/?f=+x%5E%7B2%7D+-64x+%5Cgeq+0)
![x^{2} -64x=0](https://tex.z-dn.net/?f=+x%5E%7B2%7D+-64x%3D0)
x(x-64)=0
x=0 x-64=0
x=0 x=64 {выносим на ось ниже}
в)
![-6 x^{2} +7x-1<0](https://tex.z-dn.net/?f=-6+x%5E%7B2%7D+%2B7x-1%3C0)
{приравниваем к нулю}
![-6 x^{2} +7x-1=0](https://tex.z-dn.net/?f=-6+x%5E%7B2%7D+%2B7x-1%3D0)
{решаем через дискриминант}
D=
![(7) ^{2} -4*(-6)*(-1)=49-24=25](https://tex.z-dn.net/?f=%287%29+%5E%7B2%7D+-4%2A%28-6%29%2A%28-1%29%3D49-24%3D25)
D=5
![x_{1,2} = \frac{-7 \frac{+}{-} 5}{12}](https://tex.z-dn.net/?f=+x_%7B1%2C2%7D+%3D+%5Cfrac%7B-7+%5Cfrac%7B%2B%7D%7B-%7D+5%7D%7B12%7D+)
![x_{2} =- \frac{1}{6}](https://tex.z-dn.net/?f=+x_%7B2%7D+%3D-+%5Cfrac%7B1%7D%7B6%7D+)
{выносим на ось ниже}
Вариант 4 с-5
№1
а)
![\left \{ {{-3x \leq0 } \atop {2x-4<0}} \right.](https://tex.z-dn.net/?f=+%5Cleft+%5C%7B+%7B%7B-3x+%5Cleq0+%7D+%5Catop+%7B2x-4%3C0%7D%7D+%5Cright.+)
![\left \{ {{-3x \leq 0} \atop {2x<4}} \right. = \left \{ {{-3x \leq 0} \atop {x<2}} \right.](https://tex.z-dn.net/?f=+%5Cleft+%5C%7B+%7B%7B-3x+%5Cleq+0%7D+%5Catop+%7B2x%3C4%7D%7D+%5Cright.+%3D+%5Cleft+%5C%7B+%7B%7B-3x+%5Cleq+0%7D+%5Catop+%7Bx%3C2%7D%7D+%5Cright.+)
Подставляем значение Х в первое уравнение
![\left \{ {{-6 \leq 0} \atop {x<2}} \right.](https://tex.z-dn.net/?f=+%5Cleft+%5C%7B+%7B%7B-6+%5Cleq+0%7D+%5Catop+%7Bx%3C2%7D%7D+%5Cright.+)
б)
![\left \{ {{7x+8>9x+3} \atop {5x-4<6x+1}} \right.](https://tex.z-dn.net/?f=+%5Cleft+%5C%7B+%7B%7B7x%2B8%3E9x%2B3%7D+%5Catop+%7B5x-4%3C6x%2B1%7D%7D+%5Cright.+)
![\left \{ {{-2x>-5} \atop {-1x<5}} \right. = \left \{ {{x<2,5} \atop {x<-5}} \right.](https://tex.z-dn.net/?f=+%5Cleft+%5C%7B+%7B%7B-2x%3E-5%7D+%5Catop+%7B-1x%3C5%7D%7D+%5Cright.+%3D+%5Cleft+%5C%7B+%7B%7Bx%3C2%2C5%7D+%5Catop+%7Bx%3C-5%7D%7D+%5Cright.+)
{вносим на ось ниже}
Вариант 4 с-1
а)-6x+7
![\geq](https://tex.z-dn.net/?f=+%5Cgeq+)
3x+13
![-6x-3x \geq 13-7](https://tex.z-dn.net/?f=-6x-3x+%5Cgeq+13-7)
![-9x \geq 6](https://tex.z-dn.net/?f=-9x+%5Cgeq+6)
![x \geq - \frac{2}{3}](https://tex.z-dn.net/?f=x+%5Cgeq+-+%5Cfrac%7B2%7D%7B3%7D+)
б)
![- x^{2} +10x-21 \geq 0](https://tex.z-dn.net/?f=-+x%5E%7B2%7D+%2B10x-21+%5Cgeq+0)
![- x^{2} +10x-21=0](https://tex.z-dn.net/?f=-+x%5E%7B2%7D+%2B10x-21%3D0)
D=
![(-10) ^{2} -4*(-1)*(-21)=100-84=16](https://tex.z-dn.net/?f=%28-10%29+%5E%7B2%7D+-4%2A%28-1%29%2A%28-21%29%3D100-84%3D16)
D=4
![x_{1,2} = \frac{-10 \frac{+}{-} 4}{-2}](https://tex.z-dn.net/?f=+x_%7B1%2C2%7D+%3D+%5Cfrac%7B-10+%5Cfrac%7B%2B%7D%7B-%7D+4%7D%7B-2%7D+)
![x_{1} =7](https://tex.z-dn.net/?f=+x_%7B1%7D+%3D7)
![x_{2} =3](https://tex.z-dn.net/?f=+x_%7B2%7D+%3D3)