Answer:
1. D
"n" represents the figure. For example, the equation for figure 3 would be [tex]\frac{3(3+1)}{2}[/tex] which is equal to 6 (the amount of blocks in the figure).
2. D
In the sample equations, the 9 represents figure 9. There are consistently 3 blocks in each row with an additional block at the top of the figures. So, the equation for figure 4 would be 1+(3x4) which is equal to 13. Therefore, the equation for figure 9 would be 1+(3x9).
3. A
P represents the perimeter and the n represents the figure number (like in question 1). The correct equation for the pattern would be P=4n+8. To check it, we can plug the numbers from figure 2. The equation would look like this: 16=4(2)+8
4. B
To find the answer to this problem, we just have to work backwards. We must "divide a number by 5" so we start out with [tex]\frac{n}{5}[/tex]. "n" represents the number that we do not know yet. Then we must "add 4 to the result" so the equation will now look like this: [tex]\frac{n}{5} + 4[/tex]. The problem also states that the answer is 9. Now, the final equation looks like this: [tex]\frac{n}{5} + 4=9[/tex].
If you need to, guess and check is a good way to complete multiple choice questions (until you're able to get help). I recommend asking your teacher for a more in depth explanation if you still don't understand.
