The top square is 8. The long rectangle 19.5. The bottom rectangle is 3.
To find the average you add up all the trials (13 + 9 + 7) divided by the amounted trials (3)which equals 9.67s
14+17+11/3 = 14
16+ 21 + 19/3 = 18.67
You can use cubes to help you write an expression and model the problem by using the cubes in replace of numbers. It should be a lot easier. Then after you finish you just have to write it down. There are other ways, but this is just one.
<u><em>The Explanation:</em></u> The answer is E because you switch the number sign to the opposite (<u>Ex: 4 to -4, -10 to 10</u>). The reason why is because the A is being reflected across the x-axis.
