Б)(1/7)∧-3х+1≥(1/49)∧х+3
(1/7)∧-3х+1≥(1/7)∧2х+6, 1/7≤1(основа меньше 1)
-3х+1≤2х+6
-3х-2х≤6-1
-5х≤5
х≥-1
в)11∧-7х+1≤121∧-2х-10
11∧-7х+1≤11∧-4х-20, 11≥1(основа больше 1)
-7х+1≤-4х-20
-7х+4х≤-20-1
-3х≤-21
х≥7
<span>x^2-3xy+2y^2=3
x^2-xy-2xy+2y^2=3
x(x-y)-2y(x-y)=3
(x-y)(x-2y)=3
3(1*3 или 3*1, так как нужны корни в целых числах)
</span>
![\left \{ {{x-y=1} \atop {x-2y=3}} \right.](https://tex.z-dn.net/?f=+%5Cleft+%5C%7B+%7B%7Bx-y%3D1%7D+%5Catop+%7Bx-2y%3D3%7D%7D+%5Cright.+)
x= -1 и у= -2
или
![\left \{ {{x-y=3} \atop {x-2y=1}} \right.](https://tex.z-dn.net/?f=+%5Cleft+%5C%7B+%7B%7Bx-y%3D3%7D+%5Catop+%7Bx-2y%3D1%7D%7D+%5Cright.+)
y=2 и x=5
Х^2-12х+11=0
д=144-4×11=100
х1=(12-10)/2=1
х2=(12+10)/2=11
<span>х-5х+6х-5+25=11
2х +20 = 11
2х = - 9
х = - 4,5</span>