Consider the expressions shown below. A
B
С
-812 – 31 + 4 812 – 31 + 8 812 + 31 – 4
Complete each of the following statements with the letter that represents the expression.
(3.12 – 75 + 14) + (512 + 41 – 6) is equivalent to expression
(232 – 51 – 3) + (-1012 + 25 + 7) is equivalent to expression
(1232 – 21 – 13) + (-412 + 53 +9) is equivalent to expression

Which statement about the relative areas of δabc and δxyz is true? the area of δabc > the area of δxyz the area of δabc < the area of δxyz the area of δabc = the area of δxyz more information is needed to compare.

How to do this , and can some one explain

1. according to the internal revenue service, the mean tax refund for the year 2007 was $2,708. assume the standard deviation is $650 and that the amounts refunded follow a normal probability distribution. a. what percent of the refunds are more than $3,000? b. what percent of the refunds are more than $3,000 but less than $4,000? c. what percent of the refunds are less than $2,000?