Question

Помогите срочно
A(a-2)-a^2>5-3a
3x(3x-1)-9x^2<3x+6
5y^2-y(y+4)≧100
7c(c-2)-c(7c+1)<3

Answer 1

a(a-2)-a²>5-3a
a²-2a-a²>5-3a
-2a+3a>5
a>5
a∈(5; +∞)

3x(3x-1)-9x²<3x+6
9x²-3x-9x²<3x+6
-3x-3x<6
-6x<6
x>-1
x∈(-1; +∞)

5y²-5y(y+4)≥100
5y²-5y²-20y≥100
20y≤-100
y≤-5
y∈(-∞;  -5]

7c(c-2)-c(7c+1)<3
7c²-14c-7c²-c<3
-15c<3
c>-3/15
c>-1/5
c>-0,2
c∈(-0,2; +∞)