Consider the given function
f={(4,5),(5,6),(6,−4) ..……(1)
g={(4,−4),(6,5),(8,5)} ……..(2)
Now,
1) f+g={(4+4,5−4),(5+6,6+5),(6+8,−4+5)}={(8,1),(11,11),(14,1)}
2) f−g={(4−4,5+4),(5−6,6−5),(6−8,−4−5)}={(0,9),(−1,1),(−2,−9)}
3)2f+4g={(8,10),(10,12),(12,−8)}+{(16,−16),(24,20),(32,20)}={(8+16,10−16),(10+24,12+20),(12+32,−8+20)}={(24,−6),(34,32),(44,16)}