Răspuns:
f(x)=x-2
g(x)=7-2x
a) Pui conditia ca M∈f(x) f(0)=m
f(0)=0-2=m=> m= -2
N∈f(x) f(n)=n-2=0 n=2
m=-2 n=2
b)3f(1)-g(0)+8=
f(1)=1-2= -1
g(0)=7-2*0=7
3*(-1)-7+8=-3+1= -2
c)fog(x)=g-2=(7-2x)-2=7-2x-2=5-2x
gof(x)=7-2f=7-2(x-2)=7-2x+4=11-2x
d)gof(3)=11-2*3=11-6=5∈N
e)fog(x)=x
5-2x=x
5=x+2x
3x=5
x=5/3
f)gof(x)≤5x+2
11-2x≤5x+2
11-2≤5x+2x
9≤7x
x≥9/7
Explicație pas cu pas: