3)
(c-4)(c+4) > c²-20
c²-16 >c²-20
c²-16-c²+20 >0
4>0
4)
x(x+6)-x²<2·(3x+1)
x²+6x-x²<6x+2
x²+6x-x²-6x-2<0
-2 <0
5)
(y+5)(y-2) ≥3y-10
y²+5y-2y-10 ≥3y-10
y²+5y-2y-10-3y+10 ≥0
y² ≥0
6)
8m²-6m+1≤(3m-1)²
8m²-6m+1≤9m²-6m+1
8m²-6m+1-9m²+6m-1≤0
-m²≤0
7)
a(a-2)≥-1
a²-2a≥-1
a²-2a+1≥0
(a-1)²≥0
8)
(b+7)²>14b+40
b²+14b+49>14b+40
b²+14b+49-14b-40>0
b²+9>0
3)
(c-4)(c+4) > c²-20
c²-16 >c²-20
c²-16-c²+20 >0
4>0
4)
x(x+6)-x²<2·(3x+1)
x²+6x-x²<6x+2
x²+6x-x²-6x-2<0
-2 <0
5)
(y+5)(y-2) ≥3y-10
y²+5y-2y-10 ≥3y-10
y²+5y-2y-10-3y+10 ≥0
y² ≥0
6)
8m²-6m+1≤(3m-1)²
8m²-6m+1≤9m²-6m+1
8m²-6m+1-9m²+6m-1≤0
-m²≤0
7)
a(a-2)≥-1
a²-2a≥-1
a²-2a+1≥0
(a-1)²≥0
8)
(b+7)²>14b+40
b²+14b+49>14b+40
b²+14b+49-14b-40>0
b²+9>0