4x + 3.5x=180. How do you solve it

Using the side-splitter theorem, daniel wrote a proportion for the segment formed by luke segment de. what is ec?

Find the area of the region that is inside r=3cos(theta) and outside r=2-cos(theta). sketch the curves.

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?