Namely (x-4) (x+2) >: 0x <; -2 or x> four
g(x)=2x? + 13x+20≥0
Then (2x+5)(x+4)≥0 x≤-4 or x≥-5/2.
To sum up: x≤-4 or x> four.
(2) f(x)=x? -2x-8≥(m+2)x-m- 15
x? -(m+4)x+m+7≥0, established for all x>2.
Let y=x? -(m+4)x+m+7
Y is a parabola with an upward opening, and the vertex is the minimum.
Axis of symmetry x = (m+4)/2 >; 2m & gt; 0
As long as the vertex ≥0 holds, everything else can hold.
So 4(m+7)-(m+4)? ≥0
m? +4m- 12≤0
-6≤m≤2
All in all: 0
2.∫log4(5)/log3(4)= log4(5)* log4(3)
& lt{[log4 (5)+log4 (3)]/2}? =( 1/4)[log4 (5*3)]?
& lt 1/4[log4 (4? )= 1
∴log3 (4) > log4 (5)