(a) Put x=2,y=2, we have (2)2‌+(2)2+5×2+5×2+12 ‌=4+4+10+10+12=40≠0 (b) Put x=2,y=2, we have (2)2+(2)2‌−5×2−5×2+12 ‌=4+4−10−10+12=0 Put x=3,y=3, we get ‌(3)2+(3)2−5×3−5×3+12 ‌=9+9−15−15−12=30−30=0 So, both points satisfies the given equation. (c) Put x=2,y=2, we get (2)2+(2)2‌+5×2−5×2+12 ‌=4+4+10−10+12=20≠0 (d) Put x=2,y=2, we get ‌(2)2+(2)2−5×2+5×2−12 ‌=4+4−10+10−12=−4≠0