Răspuns:
3. F:R->R, f(x)=2x+4
A(a,3)= 2a+4=3
2a=-1
a=-1/2
B=(-3,-b)= -6+4=-b
-2=-b
b=2
C(2c,-1)= 4c+4=-1
c=-5/4
4.F:R->R, f(x)=ax-7
A(2,-2)=a2-7=-2
a2=5
a=2.5
5.F:R->R,f(x)=3x-2
Sa se determne coordonatele stiind ca x=y
3x-2=y
3(3x-2)=f(x)
9x-6=0
9x=6
x=3/6
A(3/6,0)
9*0-6=-6
B(0,-6)
