What's the difference between the quantities (∑∑x)2 and ∑∑x2 ?

Question 3 of 30 paul buys fruit to make smoothies. he buys 3.78 pounds of apples, 2.12 pounds of peaches, and 4.45 pounds of oranges. paul rounds each weight to the nearest tenth of a pound. about how many pounds of fruit did paul buy? (a) 10.5 pounds (b) 10.2 pounds (c) 10.4 pounds (d) 10.0 pounds 30 points

Consider the reaction 2x2y2+z2⇌2x2y2z which has a rate law of rate= k[x2y2][z2] select a possible mechanism for the reaction.

65 8 7 4 5 6 8 4 3 2 1 9 5 6 4 2 1 6 5 1 5 1 3 2 3 5 multiply the third number in the first row by the seventh number in the third row. add this result to the fifth number in the second row. add to this total ten times the fourth number in the third row. subtract the eighth number in the first row from the result.