In your head, you should be able to add 15 and 5. The answer is 20. You should also be able to work out 20 + 9. The answer is 29. The trick to doing well at these types of questions is finding the quickest and easiest method of working them out. It will come with practice :)
Answer:
i would go for the first one but im not entirely sure
i suggest you wait to see other people's answers
X increases by one
y increases by 2
(5, 1) - > (x + 1, y + 2) -> (6, 3)
1/3(12x-24)=16
*3 *3
12x-24=48
+24 +24
12x=72
/12 /12
x=6
