What is a solution to the following system of equations?

x2 + y2 = 13
2x - y = 4

Identify the number 127 as a rational or irrational. explain

4. (10.03 mc) the equation of line cd is y = −2x − 2. write an equation of a line parallel to line cd in slope-intercept form that contains point (4, 5). (4 points) y = −2x + 13 y = negative 1 over 2 x + 7 y = negative 1 over 2 x + 3 − 2x − 3

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?