The fraction in the beginning is throwing me

Add the two expressions 3.8b - 7 and 2.9b + 9 enter your answer in simplified form

The center of the circumscribed circle lies on line segment and the longest side of the triangle is equal to the of the circle.

Jalen charges $25.50 for every 3 hours of yard work he does for his neighbors. ralph charges $34 for every 4 hours of work that he does. who charges less? opinions: 1.they charge the same amount 2.jalen 3.ralph