i need help please step by step hurry

Answer:
Step-by-step explanation:
10 x 21 - 61
210 - 61= 149
18 x 8 + 5
144 + 5= 149
21 + 10= 31
(Don't need to right this part down)
Since the 149 is parallel or the same size on the opposite side, it should be the same answer