How do u slove the expression for 4 tens+6 tens

Both the red and blue line segments stretch from the center of the circle to a point on the circle. the length of the blue segment is 5. how long is the red line segment?

Sole with work in 10 years, the average number of hours of tv watched per week by teenagers dropped from 23.9 to 21.4. find the percent of change.

If angle 2=3x +1 and angle 3=2x +4what is angle 2